WorldWideScience

Sample records for access mri system

  1. Posture-Dependent Human 3He Lung Imaging in an Open Access MRI System: Initial Results

    CERN Document Server

    Tsai, L L; Li, C -H; Rosen, M S; Patz, S; Walsworth, R L

    2007-01-01

    The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation. However, study of these effects is difficult. The conventional high-field magnets used for most hyperpolarized 3He MRI of the human lung, and most other common radiological imaging modalities including PET and CT, restrict subjects to lying horizontally, minimizing most gravitational effects. In this paper, we briefly review the motivation for posture-dependent studies of human lung function, and present initial imaging results of human lungs in the supine and vertical body orientations using inhaled hyperpolarized 3He gas and an open-access MRI instrument. The open geometry of this MRI system features a "walk-in" capability that permits subjects to be imaged in vertical and horizontal positions, and potentially allows for complete rotation of the orientation of the imaging su...

  2. Open-Access, Low-Magnetic-Field MRI System for Lung Research

    Science.gov (United States)

    Mair, Ross W.; Rosen, Matthew S.; Tsai, Leo L.; Walsworth, Ronald L.; Hrovat, Mirko I.; Patz, Samuel; Ruset, Iullian C.; Hersman, F. William

    2009-01-01

    An open-access magnetic resonance imaging (MRI) system is being developed for use in research on orientational/gravitational effects on lung physiology and function. The open-access geometry enables study of human subjects in diverse orientations. This system operates at a magnetic flux density, considerably smaller than the flux densities of typical other MRI systems, that can be generated by resistive electromagnet coils (instead of the more-expensive superconducting coils of the other systems). The human subject inhales air containing He-3 or Xe-129 atoms, the nuclear spins of which have been polarized by use of a laser beam to obtain a magnetic resonance that enables high-resolution gas space imaging at the low applied magnetic field. The system includes a bi-planar, constant-current, four-coil electromagnet assembly and associated electronic circuitry to apply a static magnetic field of 6.5 mT throughout the lung volume; planar coils and associated circuitry to apply a pulsed magnetic-field-gradient for each spatial dimension; a single, detachable radio-frequency coil and associated circuitry for inducing and detecting MRI signals; a table for supporting a horizontal subject; and electromagnetic shielding surrounding the electromagnet coils.

  3. Orientation-Dependent 3He Lung Imaging in an Open Access, Very-Low-Field Human MRI System

    CERN Document Server

    Mair, R W; Patz, S; Rosen, M S; Ruset, I C; Topulos, G P; Tsai, L L; Butler, J P; Hersman, F W; Walsworth, R L

    2004-01-01

    Orientation-dependent imaging of human lungs is demonstrated using inhaled laser-polarized 3He gas and an open-access very-low-magnetic field (< 5 mT) MRI instrument. This prototype device employs a simple, low-cost electromagnet, with an open geometry that allows variation of the orientation of the imaging subject in a two-dimensional plane. Two-dimensional 3He images were acquired with 2 mm in-plane resolution from a subject in two orientations: lying supine, and sitting in a vertical position with one arm raised. The images show clear differences in lung shape and inhaled 3He gas distribution, consistent with the expected orientation dependence of pulmonary physiology.

  4. OGIS Access System

    Data.gov (United States)

    National Archives and Records Administration — The OGIS Access System (OAS) provides case management, stakeholder collaboration, and public communications activities including a web presence via a web portal.

  5. MRI of central nervous system anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Izawa, M.; Oikawa, A.; Matoba, A.

    1987-05-01

    MRI was very useful in the evaluation of congenital anomalies of central nervous system as well as other nervous system disease with three-dimensional spatial resolution. We had experienced MRI of central nervous system anomalies, demonstrated characterisitic findings in each anomaly. MRI is useful to observe the coronal, horizontal and sagittal images of the brain and spinal cord in order to discuss the etiological mechanisms of spinal dysraphysm and its associated anomalies. In case of spina bifida cystica MRI was available to decide operative indication for radical operation and tetherd cord developed from postoperative scar or accompanied intraspinal lesions.

  6. MRI of central nervous system anomalies

    International Nuclear Information System (INIS)

    MRI was very useful in the evaluation of congenital anomalies of central nervous system as well as other nervous system disease with three-dimensional spatial resolution. We had experienced MRI of central nervous system anomalies, demonstrated characterisitic findings in each anomaly. MRI is useful to observe the coronal, horizontal and sagittal images of the brain and spinal cord in order to discuss the etiological mechanisms of spinal dysraphysm and its associated anomalies. In case of spina bifida cystica MRI was available to decide operative indication for radical operation and tetherd cord developed from postoperative scar or accompanied intraspinal lesions. (author)

  7. Central nervous system tuberculosis: MRI

    International Nuclear Information System (INIS)

    The MRI findings of 18 proven cases of central nervous system (CNS) tuberculosis were reviewed; 10 patients were seropositive for HIV. All had medical, laboratory, or surgical proof of CNS tuberculosis. Eleven patients had meningitis, of whom two also had arachnoiditis. Five patients had focal intra-axial tuberculomas: four brain masses and one an intramedullary spinal lesion. Two patients had focal extra-axial tuberculomas: one in the pontine cistern, and one in the spine. In all 11 patients with meningitis MRI showed diffuse, thick, meningeal enhancement. All intraparenchymal tuberculomas showed low signal intensity on T2-weighted images and ring or nodular enhancement. The extra-axial tuberculomas had areas isointense or hypointense relative to normal brain and spinal cord on T2-weighted images. Although tuberculous meningitis cannot be differentiated from other meningitides on the basis of MR findings, intraparenchymal tuberculomas show characteristic T2 shortening, not found in most other space-occupying lesions. In the appropriate clinical setting, tuberculoma should be considered. (orig.)

  8. Computer Security Systems Enable Access.

    Science.gov (United States)

    Riggen, Gary

    1989-01-01

    A good security system enables access and protects information from damage or tampering, but the most important aspects of a security system aren't technical. A security procedures manual addresses the human element of computer security. (MLW)

  9. Timing of MRI in pregnancy, repeat exams, access, and physician qualifications.

    Science.gov (United States)

    Levine, Deborah

    2013-10-01

    This review addresses specific questions regarding performance and utility of fetal MR. The specific issues addressed are (1) physician qualifications; (2) MR safety; (3) access to fetal MR; (4) timing of MRI in pregnancy; (5) repeat exams; and (6) when MRI is most effective for prenatal diagnosis. Fetal MRI is a problem-solving tool used for specific indications that are driven by ultrasound or at times by family history. Fetal MR should always be performed with knowledge of the sonographic findings from prior targeted scan. The best evidence for utility of MR is in assessment of CNS anomalies and assessment of the fetus with airway obstruction requiring decisions regarding mode of therapy. The type of information provided by MR can profoundly impact patient counseling and management. We recommend a team approach including specialists in obstetric imaging, fetal MRI, and postnatal care in interpreting MR so that the best information can be given to the pregnant patient. PMID:24176157

  10. Access control system for ISABELLE

    International Nuclear Information System (INIS)

    An access system based on the one now in operation at the CERN ISR is recommended. Access doors would presumably be located at the entrances to the utility tunnels connecting the support buildings with the ring. Persons requesting access would insert an identity card into a scanner to activate the system. The request would be autologged, the keybank adjacent to the door would be unlocked and ISABELLE operations would be notified. The operator would then select the door, activating a TV-audio link. The person requesting entry would draw a key from the bank, show it and his film badge to the operator who would enable the door release

  11. Scalable multichannel MRI data acquisition system.

    Science.gov (United States)

    Bodurka, Jerzy; Ledden, Patrick J; van Gelderen, Peter; Chu, Renxin; de Zwart, Jacco A; Morris, Doug; Duyn, Jeff H

    2004-01-01

    A scalable multichannel digital MRI receiver system was designed to achieve high bandwidth echo-planar imaging (EPI) acquisitions for applications such as BOLD-fMRI. The modular system design allows for easy extension to an arbitrary number of channels. A 16-channel receiver was developed and integrated with a General Electric (GE) Signa 3T VH/3 clinical scanner. Receiver performance was evaluated on phantoms and human volunteers using a custom-built 16-element receive-only brain surface coil array. At an output bandwidth of 1 MHz, a 100% acquisition duty cycle was achieved. Overall system noise figure and dynamic range were better than 0.85 dB and 84 dB, respectively. During repetitive EPI scanning on phantoms, the relative temporal standard deviation of the image intensity time-course was below 0.2%. As compared to the product birdcage head coil, 16-channel reception with the custom array yielded a nearly 6-fold SNR gain in the cerebral cortex and a 1.8-fold SNR gain in the center of the brain. The excellent system stability combined with the increased sensitivity and SENSE capabilities of 16-channel coils are expected to significantly benefit and enhance fMRI applications. PMID:14705057

  12. Positioning device for MRI-guided high intensity focused ultrasound system

    Energy Technology Data Exchange (ETDEWEB)

    Damianou, Christakis [Frederick Institute of Technology (FIT), Limassol (Cyprus); MEDSONIC, LTD, Limassol (Cyprus); Ioannides, Kleanthis [Polikliniki Igia, Limassol (Cyprus); Milonas, Nicos [Frederick Institute of Technology (FIT), Limassol (Cyprus)

    2008-04-15

    A prototype magnetic resonance imaging (MRI)- compatible positioning device was used to move an MRI-guided high intensity focused ultrasound (HIFU) transducer. The positioning device has three user-controlled degrees of freedom that allow access to various targeted lesions. The positioning device was designed and fabricated using construction materials selected for compatibility with high magnetic fields and fast switching magnetic field gradients encountered inside MRI scanners. The positioning device incorporates only MRI compatible materials such as piezoelectric motors, plastic sheets, brass screws, plastic pulleys and timing belts. The HIFU/MRI system includes the multiple subsystems (a) HIFU system, (b) MR imaging, (c) Positioning device (robot) and associate drivers, (d) temperature measurement, (e) cavitation detection, (f) MRI compatible camera, and (g) Soft ware. The MRI compatibility of the system was successfully demonstrated in a clinical high-field MRI scanner. The ability of the robot to accurately move the transducer thus creating discrete and overlapping lesions in biological tissue was tested successfully. A simple, cost effective, portable positioning device has been developed which can be used in virtually any clinical MRI scanner since it can be sited on the scanner's table. The propagation of HIFU can use either a lateral or superior-inferior approach. Discrete and large lesions were created successfully with reproducible results. (orig.)

  13. Positioning device for MRI-guided high intensity focused ultrasound system

    International Nuclear Information System (INIS)

    A prototype magnetic resonance imaging (MRI)- compatible positioning device was used to move an MRI-guided high intensity focused ultrasound (HIFU) transducer. The positioning device has three user-controlled degrees of freedom that allow access to various targeted lesions. The positioning device was designed and fabricated using construction materials selected for compatibility with high magnetic fields and fast switching magnetic field gradients encountered inside MRI scanners. The positioning device incorporates only MRI compatible materials such as piezoelectric motors, plastic sheets, brass screws, plastic pulleys and timing belts. The HIFU/MRI system includes the multiple subsystems (a) HIFU system, (b) MR imaging, (c) Positioning device (robot) and associate drivers, (d) temperature measurement, (e) cavitation detection, (f) MRI compatible camera, and (g) Soft ware. The MRI compatibility of the system was successfully demonstrated in a clinical high-field MRI scanner. The ability of the robot to accurately move the transducer thus creating discrete and overlapping lesions in biological tissue was tested successfully. A simple, cost effective, portable positioning device has been developed which can be used in virtually any clinical MRI scanner since it can be sited on the scanner's table. The propagation of HIFU can use either a lateral or superior-inferior approach. Discrete and large lesions were created successfully with reproducible results. (orig.)

  14. Computer access security code system

    Science.gov (United States)

    Collins, Earl R., Jr. (Inventor)

    1990-01-01

    A security code system for controlling access to computer and computer-controlled entry situations comprises a plurality of subsets of alpha-numeric characters disposed in random order in matrices of at least two dimensions forming theoretical rectangles, cubes, etc., such that when access is desired, at least one pair of previously unused character subsets not found in the same row or column of the matrix is chosen at random and transmitted by the computer. The proper response to gain access is transmittal of subsets which complete the rectangle, and/or a parallelepiped whose opposite corners were defined by first groups of code. Once used, subsets are not used again to absolutely defeat unauthorized access by eavesdropping, and the like.

  15. Automated Computer Access Request System

    Science.gov (United States)

    Snook, Bryan E.

    2010-01-01

    The Automated Computer Access Request (AutoCAR) system is a Web-based account provisioning application that replaces the time-consuming paper-based computer-access request process at Johnson Space Center (JSC). Auto- CAR combines rules-based and role-based functionality in one application to provide a centralized system that is easily and widely accessible. The system features a work-flow engine that facilitates request routing, a user registration directory containing contact information and user metadata, an access request submission and tracking process, and a system administrator account management component. This provides full, end-to-end disposition approval chain accountability from the moment a request is submitted. By blending both rules-based and rolebased functionality, AutoCAR has the flexibility to route requests based on a user s nationality, JSC affiliation status, and other export-control requirements, while ensuring a user s request is addressed by either a primary or backup approver. All user accounts that are tracked in AutoCAR are recorded and mapped to the native operating system schema on the target platform where user accounts reside. This allows for future extensibility for supporting creation, deletion, and account management directly on the target platforms by way of AutoCAR. The system s directory-based lookup and day-today change analysis of directory information determines personnel moves, deletions, and additions, and automatically notifies a user via e-mail to revalidate his/her account access as a result of such changes. AutoCAR is a Microsoft classic active server page (ASP) application hosted on a Microsoft Internet Information Server (IIS).

  16. Remotely Accessible Management System (RAMS).

    Science.gov (United States)

    Wood, Rex

    Oakland Schools, an Intermediate School District for Administration, operates a Remotely Accessible Management System (RAMS). RAMS is composed of over 100 computer programs, each of which performs procedures on the files of the 28 local school districts comprising the constituency of Oakland Schools. This regional service agency covers 900 square…

  17. An MRI system for imaging neonates in the NICU: initial feasibility study

    International Nuclear Information System (INIS)

    Transporting premature infants from a neonatal intensive care unit (NICU) to a radiology department for MRI has medical risks and logistical challenges. To develop a small 1.5-T MRI system for neonatal imaging that can be easily installed in the NICU and to evaluate its performance using a sheep model of human prematurity. A 1.5-T MRI system designed for orthopedic use was adapted for neonatal imaging. The system was used for MRI examinations of the brain, chest and abdomen in 12 premature lambs during the first hours of life. Spin-echo, fast spin-echo and gradient-echo MR images were evaluated by two pediatric radiologists. All animals remained physiologically stable throughout the imaging sessions. Animals were imaged at two or three time points. Seven brain MRI examinations were performed in seven different animals, 23 chest examinations in 12 animals and 19 abdominal examinations in 11 animals. At each anatomical location, high-quality images demonstrating good spatial resolution, signal-to-noise ratio and tissue contrast were routinely obtained within 30 min using standard clinical protocols. Our preliminary experience demonstrates the feasibility and potential of the neonatal MRI system to provide state-of-the-art MRI capabilities within the NICU. Advantages include overall reduced cost and site demands, lower acoustic noise, improved ease of access and reduced medical risk to the neonate. (orig.)

  18. An MRI system for imaging neonates in the NICU: initial feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Tkach, Jean A.; Loew, Wolfgang; Pratt, Ron G.; Daniels, Barret R.; Giaquinto, Randy O.; Winter, Patrick M.; Li, Yu; Dumoulin, Charles L. [Cincinnati Children' s Hospital Medical Center, Imaging Research Center, Department of Radiology, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Hillman, Noah H.; Jobe, Alan H.; Kallapur, Suhas G.; Merhar, Stephanie L.; Ikegami, Machiko; Whitsett, Jeffrey A. [Perinatal Institute, Cincinnati Children' s Hospital Medical Center, Division of Neonatology and Pulmonary Biology, Cincinnati, OH (United States); Kline-Fath, Beth M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2012-11-15

    Transporting premature infants from a neonatal intensive care unit (NICU) to a radiology department for MRI has medical risks and logistical challenges. To develop a small 1.5-T MRI system for neonatal imaging that can be easily installed in the NICU and to evaluate its performance using a sheep model of human prematurity. A 1.5-T MRI system designed for orthopedic use was adapted for neonatal imaging. The system was used for MRI examinations of the brain, chest and abdomen in 12 premature lambs during the first hours of life. Spin-echo, fast spin-echo and gradient-echo MR images were evaluated by two pediatric radiologists. All animals remained physiologically stable throughout the imaging sessions. Animals were imaged at two or three time points. Seven brain MRI examinations were performed in seven different animals, 23 chest examinations in 12 animals and 19 abdominal examinations in 11 animals. At each anatomical location, high-quality images demonstrating good spatial resolution, signal-to-noise ratio and tissue contrast were routinely obtained within 30 min using standard clinical protocols. Our preliminary experience demonstrates the feasibility and potential of the neonatal MRI system to provide state-of-the-art MRI capabilities within the NICU. Advantages include overall reduced cost and site demands, lower acoustic noise, improved ease of access and reduced medical risk to the neonate. (orig.)

  19. Pharmacological MRI (phMRI) of the Human Central Nervous System.

    Science.gov (United States)

    Lanfermann, H; Schindler, C; Jordan, J; Krug, N; Raab, P

    2015-10-01

    Pharmacological magnetic resonance imaging (phMRI) of the central nervous system (CNS) addresses the increasing demands in the biopharma industry for new methods that can accurately predict, as early as possible, whether novel CNS agents will be effective and safe. Imaging of physiological and molecular-level function can provide a more direct measure of a drug mechanism of action, enabling more predictive measures of drug activity. The availability of phMRI of the nervous system within the professional infrastructure of the Clinical Research Center (CRC) Hannover as proof of concept center ensures that advances in basic science progress swiftly into benefits for patients. Advanced standardized MRI techniques including quantitative MRI, kurtosis determination, functional MRI, and spectroscopic imaging of the entire brain are necessary for phMRI. As a result, MR scanners will evolve into high-precision measuring instruments for assessment of desirable and undesirable effects of drugs as the basic precondition for individually tailored therapy. The CRC's Imaging Unit with high-end large-scale equipment will allow the following unique opportunities: for example, identification of MR-based biomarkers to assess the effect of drugs (surrogate parameters), establishment of normal levels and reference ranges for MRI-based biomarkers, evaluation of the most relevant MRI sequences for drug monitoring in outpatient care. Another very important prerequisite for phMRI is the MHH Core Facility as the scientific and operational study unit of the CRC partner Hannover Medical School. This unit is responsible for the study coordination, conduction, complete study logistics, administration, and application of the quality assurance system based on required industry standards.

  20. Radio access selection in multi-radio access systems

    NARCIS (Netherlands)

    Jorgušeski, L.; Litjens, R.; Zhiyi, C.; Nikookar, H.

    2007-01-01

    Future wireless access systems will be characterized by their heterogeneity from technological point of view. It is envisaged that in certain areas end-users will have a choice between various radio accesses (RAs) such as e.g. classical cellular networks (GSM, UMTS, WiMAX, etc), WLAN hot-spots, or o

  1. Head Access Piping System Desing

    OpenAIRE

    中大路 道彦; 一宮 正和; 向坊 隆一; 前田 清彦; 永田 敬

    1994-01-01

    PNC made design studies on loop type FBR plants:a 600 MWe class in '91, and a 1300 MWe class in '93 both with the "head access" primary piping system. This paper focuses on the features of the smaller plant at first and afterwards on the extension to the larger one. The contents of the paper consist of R/V wall protection mechanism, primary piping circuit, secondary piping circuit, plant layout and then, discusses the extension of the applicability of the wall protection mechanism, primary pi...

  2. A Spectral-Scanning Magnetic Resonance Imaging (MRI) Integrated System

    OpenAIRE

    Hassibi, Arjang; Babakhani, Aydin; Hajimiri, Ali

    2008-01-01

    An integrated spectral-scanning magnetic resonance imaging (MRI) technique is implemented in a 0.12μm SiGe BiCMOS process. This system is designed for small-scale MRI applications with non-uniform and low magnetic fields. The system is capable of generating customized magnetic resonance (MR) excitation signals, and also recovering the MR response using a coherent direct conversion receiver. The operation frequency is tunable from DC to 37MHz for wide-band MRI and up to...

  3. Interventional MRI: update

    Energy Technology Data Exchange (ETDEWEB)

    Lufkin, R.B. [Department of Radiology, University of California Los Angeles, School of Medicine, 10 833 Le Comte Avenue, Los Angeles, CA 90024-1721 (United States); Gronemeyer, D.H.W.; Seibel, R.M.M. [Institute of Diagnostic and Interventional Radiology, Medical Computerscience, University Witten/Herdecke (Germany)

    1997-12-31

    Interventional MRI is in its early stages of development. Nevertheless, the design of new interventional MRI scanners that allow maximum direct access to the patient combined with the development of new interventional MRI pulse sequences and localization systems, means that the archetypal operating rooms of the 21st century may well contain dedicated interventional MRI units for combined radiological and surgical procedures. The present article looks at the state of interventional MRI today and looks ahead to what may be forthcoming in the not-too-distant future. After briefly discussing the instrumentation necessary for practical interventional MRI, the article will go on to describe a number of different approaches to, and clinical applications for, interventional MRI. The use of MRI in guiding and controlling tumor ablation, aspiration cytology and surgical biopsy of different body parts is described. (orig.) With 13 figs., 1 tab., 114 refs.

  4. Development of an outdoor MRI system for measuring flow in a living tree.

    Science.gov (United States)

    Nagata, Akiyoshi; Kose, Katsumi; Terada, Yasuhiko

    2016-04-01

    An outdoor MRI system for noninvasive, long-term measurements of sap flow in a living tree in its natural environment has been developed. An open-access, 0.2 T permanent magnet with a 160 mm gap was combined with a radiofrequency probe, planar gradient coils, electromagnetic shielding, several electrical units, and a waterproofing box. Two-dimensional cross-sectional images were acquired for a ring-porous tree, and the anatomical structures, including xylem and phloem, were identified. The MRI flow measurements demonstrated the diurnal changes in flow velocity in the stem on a per-pixel basis. These results demonstrate that our outdoor MRI system is a powerful tool for studies of water transport in outdoor trees. PMID:26896868

  5. Grain quality of drought tolerant accessions within the MRI Zemun Polje maize germplasm collection

    Energy Technology Data Exchange (ETDEWEB)

    Vancetovic, J.; Ignjatovic-Micic, D.; Bozinovic, S.; Babbic, M.; Filipovic, M.; Grcic, N.; Andjelkovic, V.

    2014-06-01

    Maize Research Institute Zemun Polje (MRI) gene bank created an elite drought tolerant core collection of 40 accessions, based on field trials and general combining ability with inbred lines from the main heterotic groups (Lancaster, Iowa Stiff Stalk Synthetic . BSSS and Iodent). A total of seven genetic groups were identified. Seven accessions showed good combining abilities with three testers from chosen heterotic groups, thus forming a distinctive genetic group (Unknown). In the present research, accessions with drought tolerance were also analyzed for grain quality, as these two traits are becoming highly important due to global warming and population growth. Kernel macronutrients contents (oil, protein and starch) were determined using Near Infrared Spectroscopy (NIR). Oil, protein and starch contents were significantly higher in introduced populations than in landraces for 0.43%, 0.12% and 0.85%, respectively (p < 0.01). The greatest progress from the selection based on the expected genetic gain ({Delta}G) for 5% selection intensity would be obtained for oil (14.74%) followed by protein (10.14%). Landraces showed the least potential for the grain quality improvement due to the lowest expected {Delta}G for the three macronutrients. The differences between macronutrient content among genetic groups defined them as potentially favourable sources for a specific trait. According to {Delta}G values, the greatest progress in breeding would be accomplished for increased oil content with accessions from the Unknown group. Identification of the accessions with several favorable traits is valuable for simultaneous breeding for drought tolerance and grain quality. (Author)

  6. Grain quality of drought tolerant accessions within the MRI Zemun Polje maize germplasm collection

    Directory of Open Access Journals (Sweden)

    Jelena Vančetović

    2014-01-01

    Full Text Available Maize Research Institute Zemun Polje (MRI gene bank created an elite drought tolerant core collection of 40 accessions, based on field trials and general combining ability with inbred lines from the main heterotic groups (Lancaster, Iowa Stiff Stalk Synthetic - BSSS and Iodent. A total of seven genetic groups were identified. Seven accessions showed good combining abilities with three testers from chosen heterotic groups, thus forming a dinstinctive genetic group (Unknown. In the present research, accessions with drought tolerance were also analyzed for grain quality, as these two traits are becoming highly important due to global warming and population growth. Kernel macronutrients contents (oil, protein and starch were determined using Near Infrared Spectroscopy (NIR. Oil, protein and starch contents were significantly higher in introduced populations than in landraces for 0.43%, 0.12% and 0.85%, respectively (p<0.01. The greatest progress from the selection based on the expected genetic gain (ΔG for 5% selection intensity would be obtained for oil (14.74% followed by protein (10.14%. Landraces showed the least potential for the grain quality improvement due to the lowest expected ΔG for the three macronutrients. The differences between macronutrient content among genetic groups defined them as potentially favourable sources for a specific trait. According to ΔG values, the greatest progress in breeding would be accomplished for increased oil content with accessions from the Unknown group. Identification of the accessions with several favorable traits is valuable for simultaneous breeding for drought tolerance and grain quality.

  7. A new access scheme in OFDMA systems

    Institute of Scientific and Technical Information of China (English)

    GU Xue-lin; YAN Wei; TIAN Hui; ZHANG Ping

    2006-01-01

    This article presents a dynamic random access scheme for orthogonal frequency division multiple access (OFDMA) systems. The key features of the proposed scheme are:it is a combination of both the distributed and the centralized schemes, it can accommodate several delay sensitivity classes,and it can adjust the number of random access channels in a media access control (MAC) frame and the access probability according to the outcome of Mobile Terminals access attempts in previous MAC frames. For floating populated packet-based networks, the proposed scheme possibly leads to high average user satisfaction.

  8. ACCESS Sub-system Performance

    Science.gov (United States)

    Kaiser, Mary Elizabeth; Morris, Matthew J.; Aldoroty, Lauren Nicole; Godon, David; Pelton, Russell; McCandliss, Stephan R.; Kurucz, Robert L.; Kruk, Jeffrey W.; Rauscher, Bernard J.; Kimble, Randy A.; Wright, Edward L.; Benford, Dominic J.; Gardner, Jonathan P.; Feldman, Paul D.; Moos, H. Warren; Riess, Adam G.; Bohlin, Ralph; Deustua, Susana E.; Dixon, William Van Dyke; Sahnow, David J.; Lampton, Michael; Perlmutter, Saul

    2016-01-01

    ACCESS: Absolute Color Calibration Experiment for Standard Stars is a series of rocket-borne sub-orbital missions and ground-based experiments designed to leverage significant technological advances in detectors, instruments, and the precision of the fundamental laboratory standards used to calibrate these instruments to enable improvements in the precision of the astrophysical flux scale through the transfer of laboratory absolute detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 to 1.7 micron bandpass.A cross wavelength calibration of the astrophysical flux scale to this level of precision over this broad a bandpass is relevant for the data used to probe fundamental astrophysical problems such as the SNeIa photometry based measurements used to constrain dark energy theories.We will describe the strategy for achieving this level of precision, the payload and calibration configuration, present sub-system test data, and the status and preliminary performance of the integration and test of the spectrograph and telescope. NASA APRA sounding rocket grant NNX14AH48G supports this work.

  9. Easy Access: Auditing the System Network

    Science.gov (United States)

    Wiech, Dean

    2013-01-01

    In today's electronic learning environment, access to appropriate systems and data is of the utmost importance to students, faculty, and staff. Without proper access to the school's internal systems, teachers could be prevented from logging on to an online learning system and students might be unable to submit course work to an online…

  10. Access control and personal identification systems

    CERN Document Server

    Bowers, Dan M

    1988-01-01

    Access Control and Personal Identification Systems provides an education in the field of access control and personal identification systems, which is essential in selecting the appropriate equipment, dealing intelligently with vendors in purchases of the equipment, and integrating the equipment into a total effective system. Access control devices and systems comprise an important part of almost every security system, but are seldom the sole source of security. In order for the goals of the total system to be met, the other portions of the security system must also be well planned and executed

  11. The LHC access system LACS and LASS

    CERN Document Server

    Ninin, P

    2005-01-01

    The LHC complex is divided into a number of zones with different levels of access controls.Inside the interlocked areas, the personnel protection is ensured by the LHC Access System.The system is made of two parts:the LHC Access Safety System and the LHC Access Control System. During machine operation,the LHC Access Safety System ensures the collective protection of the personnel against the radiation hazards arising from the operation of the accelerator by interlocking the LHC key safety elements. When the beams are off, the LHC Access Control System regulates the access to the accelerator and its many subsystems.It allows a remote, local or automatic operation of the access control equipment which verifies and identifies all users entering the controlled areas.The global architecture of the LHC Access System is now designed and is being validated to ensure that it meets the safety requirements for operation of the LHC.A pilot installation will be tested in the summer 2005 to validate the concept with the us...

  12. Modelling Access Control For Healthcare Information Systems

    OpenAIRE

    Ferreira, Ana; Chadwick, David W; Antunes, Luis

    2007-01-01

    The widening use of Information Systems, which allow the collection, extraction, storage, management and search of information, is increasing the need for information security. After a user is successfully identified and authenticated to a system, he needs to be authorised to access the resources he/she requested. Access control is part of this last process that checks if a user can access those resources. This is particularly important in the healthcare environment where there is the need to...

  13. Open Access and DSpace Institutional Repository System

    OpenAIRE

    Çelik, Sönmez; Gürdal, Gültekin; Keten, Burcu; Türkfidanı, Ata; Kutlutürk, Levent

    2013-01-01

    The Open Access movement is a social movement in academia, dedicated to the principle of open access - to information - sharing for the common good and is being supported by many scientists, publishers, and researchers in the world, today. The software that is used to operate the institutional archive systems which are the basis of the Open Access, are divided into two forms of some free open source software and paid package programs which were developed by some corporates. DSpace, whose firs...

  14. Clinical application of MRI to fetal central nervous system

    International Nuclear Information System (INIS)

    Objective: To explore the value of MRI on fetal central nervous system. Methods: Twenty-four women with complicated pregnancies, aged from 22 to 32 years (average 27 years) and with gestation from 23-39 weeks (average 30 weeks) were studied with a 1.5T superconductive MR unit within 24 hours after ultrasound studies. T2-weighted MR imaging was performed using HASTE and T1-weighted MR imaging was using FLASH. Comparison of the diagnosis of MRI and ultrasound were done with autopsy or postnatal follow-up MRI. Results: Of the 24 cases, 24 fetus were found. The fetal brain, gyrus, sulcus, corpus callosum, thalamus, cerebellum, brain stem, and spinal cord were shown more clearly on MR T2-weighted images. T1-weighted images were not as good as T2-weighted images. Twenty-seven lesions were visualized by ultrasound and thirty-one by MRI in these twenty-four fetuses. By MRI study, two cases were conformed their ultrasound diagnosis, ten cases were completed their ultrasound diagnosis, and twelve cases were made the same diagnosis as ultrasound. Conclusion: MR has advantages in displaying fetal central nervous system anatomy over ultrasound, the quality of MR images is not affected by maternal somatotype, volume of amniotic fluid, fetal skull and the pelvic skeleton of pregnant women. Based on ultrasound, MR imaging is a valuable complement to sonography in difficult cases, it can conforming, completing, even more correcting the diagnosis made by ultrasound. (authors)

  15. T₁ρ MRI of human musculoskeletal system.

    Science.gov (United States)

    Wang, Ligong; Regatte, Ravinder R

    2015-03-01

    Magnetic resonance imaging (MRI) offers the direct visualization of the human musculoskeletal (MSK) system, especially all diarthrodial tissues including cartilage, bone, menisci, ligaments, tendon, hip, synovium, etc. Conventional MRI techniques based on T1 - and T2 -weighted, proton density (PD) contrast are inconclusive in quantifying early biochemically degenerative changes in MSK system in general and articular cartilage in particular. In recent years, quantitative MR parameter mapping techniques have been used to quantify the biochemical changes in articular cartilage, with a special emphasis on evaluating joint injury, cartilage degeneration, and soft tissue repair. In this article we focus on cartilage biochemical composition, basic principles of T1ρ MRI, implementation of T1ρ pulse sequences, biochemical validation, and summarize the potential applications of the T1ρ MRI technique in MSK diseases including osteoarthritis (OA), anterior cruciate ligament (ACL) injury, and knee joint repair. Finally, we also review the potential advantages, challenges, and future prospects of T1ρ MRI for widespread clinical translation. PMID:24935818

  16. Interventional CT and MRI: a challenge for safety and cost reduction in the health care system

    Science.gov (United States)

    Groenemeyer, Dietrich H.; Seibel, Rainer M.

    1995-10-01

    For increasing safety in guidance techniques of endoscopes and instruments, fast radiologic imaging should be integrated. Magnetic resonance imaging (MRI), computer tomography (CT) and electron beam tomography (EBT) scanners permit transparency of the operative field; CT and EBT can be combined with fluoroscopy and ultrasound units. MRI avoids x ray exposure, but entails the possibility for 3 D localization. Open access and keyhole imaging allows nearly real time guidance of instruments. Combining minimally invasive techniques using endoscopes and tomographic guidance these technologies improve surgical access and reduce complications. This offers a safe access into the body and leads to the new field of interventional and surgical tomography. Important cost reduction for health care systems is possible, especially in the outpatient treatment of common diseases like disk herniation, back and tumor pain, metastasis, or arteriosclerosis. For realizing a long term cost reduction effect, these techniques have to be integrated in a quality management combining prevention, modern diagnosis, minimal access techniques and, if necessary, hospital stay with maximal access treatments as well as rehabilitation and secondary/tertiary prevention.

  17. Fetal central nervous system anomalies: fast MRI vs ultrasonography

    International Nuclear Information System (INIS)

    Objective: To evaluate the ability of fast MRI to detect fetal central nervous system (CNS) anomalies and to compare its performance with that of prenatal ultrasonography (US). Methods Forty-eight pregnant women were detected by conventional prenatal US and MRI. Twenty-two fetuses with CNS anomalies were conformed by autopsy and follow-up. The MR and US appearances of fetal CNS structure were compared to each other and to that of autopsy. Results: A total of 26 CNS anomalies were identified by autopsy (n=17) and follow-up (n=9) including anencephaly (n=6), rachischisis (n=2), encephalocele (n=3), congenital hydrocephalus (n=7), alobar holoprosencephaly (n=1), porencephalia (n=3), arachnoid cyst (n=2) and choroids plexus cyst (n=2). US diagnosed 24 CNS anomalies, the correct diagnostic rate was 92.3%, the false-positive rate was 3.8%, the missed-diagnostic rate was 3.8%. MRI diagnosed 23 CNS anomalies, the correct-diagnostic rate was 88.5%, the false-positive rate was 3.8% ,the missed-diagnostic rate was 7.7%. There was no difference between US and MRI (P>0.05), but MRI have larger FOV, higher tissues resolution, and can demonstrate gray-white matter in detail. Conclusions: MR imaging has a similar sensitivity to that of US in the detection of fetal CNS anomalies. (authors)

  18. CDC STATE System Tobacco Legislation - Youth Access

    Data.gov (United States)

    U.S. Department of Health & Human Services — 1995-2016. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation—Youth Access. The STATE...

  19. Perfusion MRI in neuro-psychiatric systemic lupus erthemathosus.

    NARCIS (Netherlands)

    Emmer, B.J.; Osch, M.J. van; Wu, O.; Steup-Beekman, G.M.; Steens, S.; Huizinga, T.W.J.; Buchem, M.A. van; Grond, J. van der

    2010-01-01

    PURPOSE: To use perfusion weighted MR to quantify any perfusion abnormalities and to determine their contribution to neuropsychiatric (NP) involvement in systemic lupus erythematosus (SLE). MATERIALS AND METHODS: We applied dynamic susceptibility contrast (DSC) perfusion MRI in 15 active NPSLE, 26 i

  20. An MRI-compatible hand sensory vibrotactile system

    International Nuclear Information System (INIS)

    Recently, the application of vibrotactile noise to the wrist or back of the hand has been shown to enhance fingertip tactile sensory perception (Enders et al 2013), supporting the potential for an assistive device worn at the wrist, that generates minute vibrations to help the elderly or patients with sensory deficit. However, knowledge regarding the detailed physiological mechanism behind this sensory improvement in the central nervous system, especially in the human brain, is limited, hindering progress in development and use of such assistive devices. To enable investigation of the impact of vibrotactile noise on sensorimotor brain activity in humans, a magnetic resonance imaging (MRI)-compatible vibrotactile system was developed to provide vibrotactile noise during an MRI of the brain. The vibrotactile system utilizes a remote (outside the MR room) signal amplifier which provides a voltage from –40 to +40 V to drive a 12 mm diameter piezoelectric vibrator (inside the MR room). It is portable and is found to be MRI-compatible which enables its use for neurologic investigation with MRI. The system was also found to induce an improvement in fingertip tactile sensation, consistent with the previous study. (note)

  1. Access Control Management for SCADA Systems

    Science.gov (United States)

    Hong, Seng-Phil; Ahn, Gail-Joon; Xu, Wenjuan

    The information technology revolution has transformed all aspects of our society including critical infrastructures and led a significant shift from their old and disparate business models based on proprietary and legacy environments to more open and consolidated ones. Supervisory Control and Data Acquisition (SCADA) systems have been widely used not only for industrial processes but also for some experimental facilities. Due to the nature of open environments, managing SCADA systems should meet various security requirements since system administrators need to deal with a large number of entities and functions involved in critical infrastructures. In this paper, we identify necessary access control requirements in SCADA systems and articulate access control policies for the simulated SCADA systems. We also attempt to analyze and realize those requirements and policies in the context of role-based access control that is suitable for simplifying administrative tasks in large scale enterprises.

  2. Performance estimates for personnel access control systems

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, R. G.

    1980-10-01

    Current performance estimates for personnel access control systems use estimates of Type I and Type II verification errors. A system performance equation which addresses normal operation, the insider, and outside adversary attack is developed. Examination of this equation reveals the inadequacy of classical Type I and II error evaluations which require detailed knowledge of the adversary threat scenario for each specific installation. Consequently, new performance measures which are consistent with the performance equation and independent of the threat are developed as an aid in selecting personnel access control systems.

  3. A wireless communication system for interventional MRI

    International Nuclear Information System (INIS)

    The available MR-compatible communication systems, which are typically designed for diagnostic exams, are mostly based on tubular sound transmission. In other settings, modern commercially available communication systems with ear protection allow wireless communication in noisy environments. The application of MR-compatible wireless headsets in interventional radiology precludes tube contact with sterile surfaces and hindrance of the interventionalist's range of motion. The system introduced here allows wireless communication within the scanner room without influencing MR image quality. (orig.)

  4. Totally Accessible MRI A User's Guide to Principles, Technology, and Applications

    CERN Document Server

    Lipton, Michael L

    2008-01-01

    This is a practical guide that offers a lucid introduction to the principles of MRI physics. The author, recognized in the imaging community for his exceptional teaching methods and lectures, has written an easy to understand text. Each chapter explains the "why" and "how" behind MRI physics. Readers will understand how altering MRI parameters will have many different consequences for image quality and the speed in which images are generated. Practical topics, selected for their value to clinical practice, include progressive changes in key MRI parameters, imaging time, and signal to noise ratio. A wealth of high quality illustrations, complemented by concise text, enables readers to gain a thorough understanding of the subject without requiring prior in-depth knowledge

  5. Distributed Access View Integrated Database (DAVID) system

    Science.gov (United States)

    Jacobs, Barry E.

    1991-01-01

    The Distributed Access View Integrated Database (DAVID) System, which was adopted by the Astrophysics Division for their Astrophysics Data System, is a solution to the system heterogeneity problem. The heterogeneous components of the Astrophysics problem is outlined. The Library and Library Consortium levels of the DAVID approach are described. The 'books' and 'kits' level is discussed. The Universal Object Typer Management System level is described. The relation of the DAVID project with the Small Business Innovative Research (SBIR) program is explained.

  6. Access Control in Data Management Systems

    CERN Document Server

    Ferrari, Elena

    2010-01-01

    Access control is one of the fundamental services that any Data Management System should provide. Its main goal is to protect data from unauthorized read and write operations. This is particularly crucial in today's open and interconnected world, where each kind of information can be easily made available to a huge user population, and where a damage or misuse of data may have unpredictable consequences that go beyond the boundaries where data reside or have been generated. This book provides an overview of the various developments in access control for data management systems. Discretionary,

  7. Superconductors Enable Lower Cost MRI Systems

    Science.gov (United States)

    2013-01-01

    The future looks bright, light, and green, especially where aircraft are concerned. The division of NASA s Fundamental Aeronautics Program called the Subsonic Fixed Wing Project is aiming to reach new heights by 2025-2035, improving the efficiency and environmental impact of air travel by developing new capabilities for cleaner, quieter, and more fuel efficient aircraft. One of the many ways NASA plans to reach its aviation goals is by combining new aircraft configurations with an advanced turboelectric distributed propulsion (TeDP) system. Jeff Trudell, an engineer at Glenn Research Center, says, "The TeDP system consists of gas turbines generating electricity to power a large number of distributed motor-driven fans embedded into the airframe." The combined effect increases the effective bypass ratio and reduces drag to meet future goals. "While room temperature components may help reduce emissions and noise in a TeDP system, cryogenic superconducting electric motors and generators are essential to reduce fuel burn," says Trudell. Superconductors provide significantly higher current densities and smaller and lighter designs than room temperature equivalents. Superconductors are also able to conduct direct current without resistance (loss of energy) below a critical temperature and applied field. Unfortunately, alternating current (AC) losses represent the major part of the heat load and depend on the frequency of the current and applied field. A refrigeration system is necessary to remove the losses and its weight increases with decreasing temperature. In 2001, a material called magnesium diboride (MgB2) was discovered to be superconducting. The challenge, however, has been learning to manufacture MgB2 inexpensively and in long lengths to wind into large coils while meeting the application requirements.

  8. Safety testing for LHC access system

    CERN Document Server

    Valentini, F; Ninin, P; Scibile, S

    2008-01-01

    In the domain of Safety Real-Time Systems the problem of testing represents always a big effort in terms of time, costs and efficiency to guarantee an adequate coverage degree. Exhaustive tests may, in fact, not be practicable for large and distributed systems. This paper describes the testing process followed during the validation of the CERN's LHC Access System [1], responsible for monitoring and preventing physical risks for the personnel accessing the underground areas. In the paper we also present a novel strategy for the testing problem, intended to drastically reduce the time for the test patterns generation and execution. In particular, we propose a methodology for blackbox testing that relies on the application of Model Checking techniques. Model Checking is a formal method from computer science, commonly adopted to prove correctness of system’s models through an automatic system’s state space exploration against some property formulas.

  9. LANSCE personnel access control system (PACS)

    International Nuclear Information System (INIS)

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. The Personnel Access Control System (PACS) is a component of the RSS that is designed to prevent personnel access to areas where prompt radiation is a hazard. PACS was designed to replace several older personnel safety systems (PSS) with a single modem unified design. Lessons learned from the operation over the last 20 years were incorporated into a redundant sensor, single-point failure safe, fault tolerant, and tamper-resistant system that prevents access to the beam areas by controlling the access keys and beam stoppers. PACS uses a layered philosophy to the physical and electronic design. The most critical assemblies are battery backed up, relay logic circuits; less critical devices use Programmable Logic Controllers (PLCs) for timing functions and communications. Outside reviewers have reviewed the operational safety of the design. The design philosophy, lessons learned, hardware design, software design, operation, and limitations of the device are described

  10. OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging Studies. Core set of MRI acquisitions, joint pathology definitions, and the OMERACT RA-MRI scoring system

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Peterfy, C; Conaghan, P;

    2003-01-01

    This article describes the 2002 OMERACT rheumatoid arthritis magnetic resonance image scoring system (RAMRIS) for evaluation of inflammatory and destructive changes in RA hands and wrists, which was developed by an international MRI-OMERACT group. MRI definitions of important RA joint pathologies......, and a 'core set' of basic MRI sequences for use in RA are also suggested...

  11. Analysis of systemic lupus erythematosus (SLE) involving the central nervous system by magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Involvement of the central nervous system (CNS) commonly occurs in systemic lupus erythematosus (SLE). But definitive diagnosis remains difficult even with computed tomography (CT). In this study, we used the recently developed technique, magnetic resonance imaging (MRI) for CNS lupus and compared it with CT scans. CT was performed with a General Electric 8800 CT/T scanner. MRI was performed using a Mitsubishi Electric MMI-150 S. Ten patients with CNS lupus were divided into 3 groups. Group I included 4 cases with neurological manifestations alone. All lesions seen on CT were also detected by MRI, with greater clarity and extent. Furthermore, MRI depicted several microinfarcts in white matter without symptoms. Group II included 5 cases with psychiatric features alone. MRI detected a thalamic microinfarct in only one case while CT showed no abnormality in all cases. Group III included 1 case with both neurological and psychiatric symptoms. MRI demonstrated a small infarct of midbrain corresponding with neurological symptoms, more clearly than CT. Therefore MRI demonstrates the degree of brain involvement in SLE more accurately than CT. (author)

  12. Value of prenatal MRI in early evaluation of fetal central nervous system anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Keiichi [Kugayama Hospital, Tokyo (Japan); Nakamura, Masanao; Hino, Ken [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine] [and others

    2002-08-01

    Advances in technology and the need for accurate prenatal diagnoses have produced great improvements in fetal diagnosis by MRI. However, there are still many problems with diagnosis of central nervous system (CNS) anomalies using MRI (e.g., time of diagnosis, factors limiting diagnostic ability. Fifteen cases referred to our clinic from 1992 to 2001 and examined using intrauterine ultrasound, prenatal MRI and postnatal MRI were reviewed retrospectively. All clinical records and findings from prenatal MRI, postnatal MRI and ultrasound were reviewed. Prenatal MRI was found to be equal in diagnostic power to ultrasound and postnatal MRI in 10 of the 15 cases. In the remaining 5 fetuses, the findings of prenatal MRI were not the same to those of prenatal ultrasound and postnatal MRI. Our goal was to determine the value of prenatal MRI in diagnosis of fetal CNS anomalies, to ascertain how this information might be used for counseling, and to assess its impact on pregnancy management. Prenatal MRI provided useful information for support personnel (e.g., physicians, nurses, caseworkers, religious advisers). (author)

  13. OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging Studies. Core set of MRI acquisitions, joint pathology definitions, and the OMERACT RA-MRI scoring system

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Peterfy, C; Conaghan, P;

    2003-01-01

    This article describes the 2002 OMERACT rheumatoid arthritis magnetic resonance image scoring system (RAMRIS) for evaluation of inflammatory and destructive changes in RA hands and wrists, which was developed by an international MRI-OMERACT group. MRI definitions of important RA joint pathologies......, and a 'core set' of basic MRI sequences for use in RA are also suggested......This article describes the 2002 OMERACT rheumatoid arthritis magnetic resonance image scoring system (RAMRIS) for evaluation of inflammatory and destructive changes in RA hands and wrists, which was developed by an international MRI-OMERACT group. MRI definitions of important RA joint pathologies...

  14. Science information systems: Archive, access, and retrieval

    Science.gov (United States)

    Campbell, William J.

    1991-01-01

    The objective of this research is to develop technology for the automated characterization and interactive retrieval and visualization of very large, complex scientific data sets. Technologies will be developed for the following specific areas: (1) rapidly archiving data sets; (2) automatically characterizing and labeling data in near real-time; (3) providing users with the ability to browse contents of databases efficiently and effectively; (4) providing users with the ability to access and retrieve system independent data sets electronically; and (5) automatically alerting scientists to anomalies detected in data.

  15. Quantitative evaluation of the reticuloendothelial system function with dynamic MRI.

    Directory of Open Access Journals (Sweden)

    Ting Liu

    Full Text Available PURPOSE: To evaluate the reticuloendothelial system (RES function by real-time imaging blood clearance as well as hepatic uptake of superparamagnetic iron oxide nanoparticle (SPIO using dynamic magnetic resonance imaging (MRI with two-compartment pharmacokinetic modeling. MATERIALS AND METHODS: Kinetics of blood clearance and hepatic accumulation were recorded in young adult male 01b74 athymic nude mice by dynamic T2* weighted MRI after the injection of different doses of SPIO nanoparticles (0.5, 3 or 10 mg Fe/kg. Association parameter, Kin, dissociation parameter, Kout, and elimination constant, Ke, derived from dynamic data with two-compartment model, were used to describe active binding to Kupffer cells and extrahepatic clearance. The clodrosome and liposome were utilized to deplete macrophages and block the RES function to evaluate the capability of the kinetic parameters for investigation of macrophage function and density. RESULTS: The two-compartment model provided a good description for all data and showed a low sum squared residual for all mice (0.27±0.03. A lower Kin, a lower Kout and a lower Ke were found after clodrosome treatment, whereas a lower Kin, a higher Kout and a lower Ke were observed after liposome treatment in comparison to saline treatment (P<0.005. CONCLUSION: Dynamic SPIO-enhanced MR imaging with two-compartment modeling can provide information on RES function on both a cell number and receptor function level.

  16. Decentralized energy systems for clean electricity access

    Science.gov (United States)

    Alstone, Peter; Gershenson, Dimitry; Kammen, Daniel M.

    2015-04-01

    Innovative approaches are needed to address the needs of the 1.3 billion people lacking electricity, while simultaneously transitioning to a decarbonized energy system. With particular focus on the energy needs of the underserved, we present an analytic and conceptual framework that clarifies the heterogeneous continuum of centralized on-grid electricity, autonomous mini- or community grids, and distributed, individual energy services. A historical analysis shows that the present day is a unique moment in the history of electrification where decentralized energy networks are rapidly spreading, based on super-efficient end-use appliances and low-cost photovoltaics. We document how this evolution is supported by critical and widely available information technologies, particularly mobile phones and virtual financial services. These disruptive technology systems can rapidly increase access to basic electricity services and directly inform the emerging Sustainable Development Goals for quality of life, while simultaneously driving action towards low-carbon, Earth-sustaining, inclusive energy systems.

  17. Adapting MRI systems to propel and guide microdevices in the human blood circulatory system.

    Science.gov (United States)

    Martel, S; Mathieu, J B; Felfoul, O; Macicior, H; Beaudoin, G; Soulez, G; Yahia, L H

    2004-01-01

    Magnetic resonance imaging (MRI) systems are widely used to gather noninvasively images of the interior of the human body. This paper suggests that an MRI system can be seen beyond being just a tool for imaging purpose but one that can propel and guide special microdevices in the human body to perform specific medical tasks. More specifically, an MRI system can potentially be used to image the region of interest, propel a microdevice through the generation of magnetic gradients, determine the location of the device, compute the corrective actions through feedback control algorithms and adjust the generation of the magnetic gradients accordingly to navigate such a microdevice in a preplanned path. This paper presents an introductory description of the proposed techniques, the main issues to consider, and some preliminary data indicating the validity of this approach.

  18. Digital Autonomous Terminal Access Communication (DATAC) system

    Science.gov (United States)

    Novacki, Stanley M., III

    1987-01-01

    In order to accommodate the increasing number of computerized subsystems aboard today's more fuel efficient aircraft, the Boeing Co. has developed the DATAC (Digital Autonomous Terminal Access Control) bus to minimize the need for point-to-point wiring to interconnect these various systems, thereby reducing total aircraft weight and maintaining an economical flight configuration. The DATAC bus is essentially a local area network providing interconnections for any of the flight management and control systems aboard the aircraft. The task of developing a Bus Monitor Unit was broken down into four subtasks: (1) providing a hardware interface between the DATAC bus and the Z8000-based microcomputer system to be used as the bus monitor; (2) establishing a communication link between the Z8000 system and a CP/M-based computer system; (3) generation of data reduction and display software to output data to the console device; and (4) development of a DATAC Terminal Simulator to facilitate testing of the hardware and software which transfer data between the DATAC's bus and the operator's console in a near real time environment. These tasks are briefly discussed.

  19. Research of user access control for networked manufacturing system

    Institute of Scientific and Technical Information of China (English)

    ZHENG Xiao-lin; LEI Yu; CHEN De-ren

    2006-01-01

    An integrated user access control method was proposed to address the issues of security and management in networked manufacturing systems (NMS).Based on the analysis of the security issues in networked manufacturing system,an integrated user access control method composed of role-based access control (RBAC),task-based access control (TBAC),relationship-driven access control (RDAC)and coalition-based access control (CBAC) was proposed,including the hierarchical user relationship model,the reference model and the process model.The elements and their relationships were defined,and the expressions of constraints authorization were given.The extensible access control markup language (XACML) was used to implement this method.This method was used in the networked manufacturing system in the Shaoxing spinning region of China.The results show that the integrated user access control method can reduce the costs of system security maintenance and management.

  20. Diffusion microscopist simulator - The development and application of a Monte Carlo simulation system for diffusion MRI

    International Nuclear Information System (INIS)

    Diffusion magnetic resonance imaging (dMRI) has made a significant breakthrough in neurological disorders and brain research thanks to its exquisite sensitivity to tissue cyto-architecture. However, as the water diffusion process in neuronal tissues is a complex biophysical phenomena at molecular scale, it is difficult to infer tissue microscopic characteristics on a voxel scale from dMRI data. The major methodological contribution of this thesis is the development of an integrated and generic Monte Carlo simulation framework, 'Diffusion Microscopist Simulator' (DMS), which has the capacity to create 3D biological tissue models of various shapes and properties, as well as to synthesize dMRI data for a large variety of MRI methods, pulse sequence design and parameters. DMS aims at bridging the gap between the elementary diffusion processes occurring at a micrometric scale and the resulting diffusion signal measured at millimetric scale, providing better insights into the features observed in dMRI, as well as offering ground-truth information for optimization and validation of dMRI acquisition protocols for different applications. We have verified the performance and validity of DMS through various benchmark experiments, and applied to address particular research topics in dMRI. Based on DMS, there are two major application contributions in this thesis. First, we use DMS to investigate the impact of finite diffusion gradient pulse duration (delta) on fibre orientation estimation in dMRI. We propose that current practice of using long delta, which is enforced by the hardware limitation of clinical MRI scanners, is actually beneficial for mapping fibre orientations, even though it violates the underlying assumption made in q-space theory. Second, we employ DMS to investigate the feasibility of estimating axon radius using a clinical MRI system. The results suggest that the algorithm for mapping the direct microstructures is applicable to dMRI data acquired from

  1. Context-Based E-Health System Access Control Mechanism

    Science.gov (United States)

    Al-Neyadi, Fahed; Abawajy, Jemal H.

    E-Health systems logically demand a sufficiently fine-grained authorization policy for access control. The access to medical information should not be just role-based but should also include the contextual condition of the role to access data. In this paper, we present a mechanism to extend the standard role-based access control to incorporate contextual information for making access control decisions in e-health application. We present an architecture consisting of authorisation and context infrastructure that work cooperatively to grant access rights based on context-aware authorization policies and context information.

  2. Third Degree Skin Burns Caused by an MRI Compatible Electrocardiographic Monitoring System

    DEFF Research Database (Denmark)

    Brix, Lau; Isaksen, Christin Rosendahl Graff; Kristensen, Birgitte Hornbæk;

    burns caused by the ECG cables are less common [1]. This case report presents two unusual cases of skin burns which were caused by MRI safe ECG leads during scanning. Cases:Two patients suffered third degree burns using MRI approved ECG leads (Medrad® Veris MR Monitor system) in a Siemens Skyra 3.......0 Tesla MRI system. MRI sequences: Turbo Spin Echo (TSE) (ETL = 2-27, Scan time = 152-235 seconds), Flip Angles 135-160°, TR = 560-5423 ms). Both patients had elongated burns located on their bellies and therefore caused by the leads and not the electrodes. Both patients were sedated and the burns were......Introduction: The combination of increased magnetic field strength, field gradients and RF power, augments the risk of tissue heating in patients undergoing an MRI examination. This is especially important when the patients have implants or when external devices are in direct contact with the skin...

  3. MRI-guided abdominal biopsy in a 0.23-T open-configuration MRI system

    Energy Technology Data Exchange (ETDEWEB)

    Kariniemi, J.; Blanco Sequeiros, R.; Ojala, R.; Tervonen, O. [University Hospital of Oulu Radiology, Oulu (Finland)

    2005-06-01

    The purpose of this study was to test the hypothesis that when ultrasound (US) guidance is not feasible, abdominal biopsies can be performed safely and accurately under magnetic resonance imaging (MRI) guidance in a low-field environment. MRI-guided abdominal biopsy was performed on 31 consecutive patients, in whom US-guided abdominal biopsy was not possible because the lesion was not visualized in US (n=27) or an US-guided procedure was not considered safe (n=4). The locations of the lesions were liver (n=14), pancreas (n=6), lymph node (n=4), retroperitoneal mass (n=3), adrenal gland (n=3) and spleen (n=1). The average size of the lesion was 2.2 cm (range 1-4 cm) in maximum diameter. All procedures were done by using a 0.23-T open-configuration C-arm-shaped MRI scanner with interventional optical tracking equipment and software. Fine-needle aspiration (FNA) biopsy was performed on all 31 patients; 18 patients underwent both FNA biopsy and cutting needle core biopsy. Procedures were evaluated for diagnostic sensitivity, specificity and accuracy as well as procedure time and complications. The FNA biopsy specimens were adequate for interpretation in 27 (87%) of 31 cases. Two of these proved to be false-negative findings during follow-up or subsequent biopsy. The final diagnosis was malignant in 15 and benign in 16 patients. The sensitivity, specificity and accuracy of FNA biopsy were 71, 100 and 81%, respectively. Of the 18 core-needle biopsies, one was determined false-negative owing to nonrepresentativeness. The sensitivity, specificity and accuracy of histological samples were 90, 100 and 94%, respectively. The needle time was 19 min on average and the mean room time was 1 h 48 min. No immediate or late complications occurred. MRI-guided abdominal biopsy can be performed safely and accurately in a low-field environment in patients for whom an US-guided procedure is not feasible. (orig.)

  4. MRI changes in the central nervous system in a child with lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Gieron, M.A. [Dept. of Pediatrics, Univ. of South Florida, Coll. of Medicine, Tampa, FL (United States); Khoromi, S. [Dept. of Neurology, Univ. of South Florida, Coll. of Medicine, Tampa, FL (United States); Campos, A. [Dept. of Pediatrics, Univ. of South Florida, Coll. of Medicine, Tampa, FL (United States)

    1995-05-01

    We report on a 10-year-old girl with systemic lupus erythematosus who presented in status epilepticus as the only manifestation of central nervous system involvement. MRI of the brain showed diffuse gray and white matter lesions which almost completely resolved after treatment with methylprednisolone. MRI findings in this child are similar to those in adults with diffuse clinical manifestations. The study is essential in the initial evaluation of patients suspected of central nervous system lupus. (orig.)

  5. The DAMASK trial protocol: a pragmatic randomised trial to evaluate whether GPs should have direct access to MRI for patients with suspected internal derangement of the knee

    Directory of Open Access Journals (Sweden)

    Orchard Jo

    2006-10-01

    Full Text Available Abstract Background Though new technologies like Magnetic Resonance Imaging (MRI may be accurate, they often diffuse into practice before thorough assessment of their value in diagnosis and management, and of their effects on patient outcome and costs. MRI of the knee is a common investigation despite concern that it is not always appropriate. There is wide variation in general practitioners (GPs access to, and use of MRI, and in the associated costs. The objective of this study was to resolve uncertainty whether GPs should refer patients with suspected internal derangement of the knee for MRI or to an orthopaedic specialist in secondary care. Methods/Design The design consisted of a pragmatic multi-centre randomised trial with two parallel groups and concomitant economic evaluation. Patients presenting in general practice with suspected internal derangement of the knee and for whom their GP was considering referral to an orthopaedic specialist in secondary care were eligible for inclusion. Within practices, GPs or practice nurses randomised eligible and consenting participants to the local radiology department for an MRI examination, or for consultation with an orthopaedic specialist. To ensure that the waiting time from GP consultation to orthopaedic appointment was similar for both trial arms, GPs made a provisional referral to orthopaedics when requesting the MRI examination. Thus we evaluated the more appropriate sequence of events independent of variations in waiting times. Follow up of participants was by postal questionnaires at six, twelve and 24 months after randomisation. This was to ensure that the evaluation covered all events up to and including arthroscopy. Discussion The DAMASK trial should make a major contribution to the development of evidence-based partnerships between primary and secondary care professionals and inform the debate when MRI should enter the diagnostic pathway.

  6. Influence of the Application of MRI on the T, N Staging System of Nasopharyngeal Carcinoma

    Institute of Scientific and Technical Information of China (English)

    ChuanmiaoXie; BilingLiang; HaogaoUn; PeihongWu

    2004-01-01

    OBJECTIVE To investigate the influence of utilizing MRI on the T, N staging system (the 5th edition, UICC) and on the 1992 China staging systems (Fuzhou-Guangzhou,China) by comparing the results of CT and MRI examinations of nasopharyngeal carcinoma (NPC).METHODS All 56 NPC patients, which were confirmed by histology,accepted both CT and MRI examinations. CT system scans were obtained by using an Elscient CT Twin Flash with the conventional axial scan. Three cases were examined by an additional coronary scan and 16 patients received an enhanced CT. The MR imaging was performed with a 0.5T MR system (Philips T5- II Ultra-Magnetic). The conventional axial, sagittal and coronary sections with SE sequences were obtained. The scan field was from the supra sellar cistern to the inferior border of C2. Most patients (50/56) accepted contrast enhanced MRI.RESULTS The pharyngobasilar fascia can clearly be seen on MRI but not on CT, so MRI can accurately determine the lesion in the nasopharyngeal cavity. MRI is more sensitive for evaluation of tumor involvement of soft tissue such as the Iongus colli muscle (14 cases by CT and 26 by MRI), tensor veli patalini muscle and levator veli palatini muscle (17 cases by CT and 23 by MRI), and skull-base bone marrow invasion (15 cases by CT and 42 by MRI). MRI can also demonstrate the invasion of the carotid sheath area and the enlargement of retropharyngeal lymph nodes more definitely than CT.The involvement of the trigeminal nerve can be detected on MRI, which may influence the clinical staging directly.CONCLUSION Of the 56 cases examined, 16 (28.6%) changed the staging based on UICC staging; while 33.9% (19/56) cases changed based on the 1992 China-stagin9 system. The major influence of MRI examinations on the 1992 staging was to differentiate the involvement of the carotid sheath area from metastasis of the retropharyngeal lymph nodes. There also was a significant difference in finding early invasion of the skull base.

  7. Multi-sensor system for simultaneous ultra-low-field MRI and MEG

    CERN Document Server

    Zotev, V S; Matlachov, A N; Mosher, J C; Newman, S G; Sandin, H J; Urbaitis, A V; Volegov, P L

    2006-01-01

    Magnetoencephalography (MEG) and magnetic resonance imaging at ultra-low fields (ULF MRI) are two methods based on the ability of SQUID (superconducting quantum interference device) sensors to detect femtotesla magnetic fields. Combination of these methods will allow simultaneous functional (MEG) and structural (ULF MRI) imaging of the human brain. In this paper, we report the first implementation of a multi-sensor SQUID system designed for both MEG and ULF MRI. We present a multi-channel image of a human hand obtained at 46 microtesla field, as well as results of auditory MEG measurements with the new system.

  8. Campus Access Control System RFID Based

    Directory of Open Access Journals (Sweden)

    Mr. SANTHOSH S

    2012-06-01

    Full Text Available Radio frequency identification (RFID technology has helped many organizations to reduce cost. Nevertheless, there are challenges and issues associated with RFID adoption. The most common internal challenge for many organizations is justifying the investment and modification of processes. The focus of this project is to show the business value of RFID technology and its applications. The important issue is the security level of the whole campus because it needs to be carefully differentiated. Dormitories and special research laboratories should benefit from higher levels of security than any other campuses. The key to the problem is represented by the new Radio Frequency Identification (RFID which can support contactless cards with memory. The most important feature of the proposed system is the updating of access permission level at any time for the user based on the availability of that user. The data transfer from the reader to the database was done using wireless communication (RF communication. To achieve this here RF transmitter and the RF receiver is used. The data which is read by the reader is sent to the microcontroller. Then from the controller we can transfer the data to the database by using the UART module (serial communication which is inbuilt in the microcontroller through RF transmitter. RF receiver of the same frequency at the receiver end receives and then stores the data in the database. RF transmitter and Receiver – frequency for transmitting and receiving the data depends on the user as per the requirement for the application and it is based on the range of distance. For the data encoding and decoding process HCS-101 protocol is used.

  9. Characterization of acoustic noise in a neonatal intensive care unit MRI system

    Energy Technology Data Exchange (ETDEWEB)

    Tkach, Jean A.; Li, Yu; Pratt, Ronald G.; Loew, Wolfgang; Daniels, Barret R.; Giaquinto, Randy O.; Dumoulin, Charles L. [Cincinnati Children' s Hospital Medical Center, Imaging Research Center, Department of Radiology, Cincinnati, OH (United States); Baroch, Kelly A. [Cincinnati Children' s Hospital Medical Center, Division of Audiology, Cincinnati, OH (United States); Merhar, Stephanie L. [Cincinnati Children' s Hospital Medical Center, Division of Neonatology and Pulmonary Biology, Perinatal Institute, Cincinnati, OH (United States); Kline-Fath, Beth M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2014-08-15

    To eliminate the medical risks and logistical challenges of transporting infants from the neonatal intensive care unit (NICU) to the radiology department for magnetic resonance imaging, a small-footprint 1.5-T MRI scanner has been developed for neonatal imaging within the NICU. MRI is known to be noisy, and exposure to excessive acoustic noise has the potential to elicit physiological distress and impact development in the term and preterm infant. To measure and compare the acoustic noise properties of the NICU MRI system against those of a conventional 1.5-T MRI system. We performed sound pressure level measurements in the NICU MRI scanner and in a conventional adult-size whole-body 1.5-T MRI system. Sound pressure level measurements were made for six standard clinical MR imaging protocols. The average sound pressure level value, reported in unweighted (dB) and A-weighted (dBA) decibels for all six imaging pulse sequences, was 73.8 dB and 88 dBA for the NICU scanner, and 87 dB and 98.4 dBA for the conventional MRI scanner. The sound pressure level values measured on the NICU scanner for each of the six MR imaging pulse sequences were consistently and significantly (P = 0.03) lower, with an average difference of 14.2 dB (range 10-21 dB) and 11 dBA (range 5-18 dBA). The sound pressure level frequency response of the two MR systems showed a similar harmonic structure above 200 Hz for all imaging sequences. The amplitude, however, was appreciably lower for the NICU scanner, by as much as 30 dB, for frequencies below 200 Hz. The NICU MRI system is quieter than conventional MRI scanners, improving safety for the neonate and facilitating siting of the unit within the NICU. (orig.)

  10. Characterization of acoustic noise in a neonatal intensive care unit MRI system

    International Nuclear Information System (INIS)

    To eliminate the medical risks and logistical challenges of transporting infants from the neonatal intensive care unit (NICU) to the radiology department for magnetic resonance imaging, a small-footprint 1.5-T MRI scanner has been developed for neonatal imaging within the NICU. MRI is known to be noisy, and exposure to excessive acoustic noise has the potential to elicit physiological distress and impact development in the term and preterm infant. To measure and compare the acoustic noise properties of the NICU MRI system against those of a conventional 1.5-T MRI system. We performed sound pressure level measurements in the NICU MRI scanner and in a conventional adult-size whole-body 1.5-T MRI system. Sound pressure level measurements were made for six standard clinical MR imaging protocols. The average sound pressure level value, reported in unweighted (dB) and A-weighted (dBA) decibels for all six imaging pulse sequences, was 73.8 dB and 88 dBA for the NICU scanner, and 87 dB and 98.4 dBA for the conventional MRI scanner. The sound pressure level values measured on the NICU scanner for each of the six MR imaging pulse sequences were consistently and significantly (P = 0.03) lower, with an average difference of 14.2 dB (range 10-21 dB) and 11 dBA (range 5-18 dBA). The sound pressure level frequency response of the two MR systems showed a similar harmonic structure above 200 Hz for all imaging sequences. The amplitude, however, was appreciably lower for the NICU scanner, by as much as 30 dB, for frequencies below 200 Hz. The NICU MRI system is quieter than conventional MRI scanners, improving safety for the neonate and facilitating siting of the unit within the NICU. (orig.)

  11. Application Performance on the Direct Access File System

    OpenAIRE

    Fedorova, Alexandra; Seltzer, Margo I.; Magoutis, Kostas; Addetia, Salimah

    2003-01-01

    The Direct Access File System (DAFS) is a distributed file system built on top of direct-access transports (DAT). Direct-access transports are characterized by using remote direct memory access (RDMA) for data transfer and user-level networking. The motivation behind the DAT-enabled distributed file system architecture is the reduction of the CPU overhead on the I/O data path. In collaboration with Duke University we have created and made available an open-source implementation of DAFS for th...

  12. A networked modular hardware and software system for MRI-guided robotic prostate interventions

    Science.gov (United States)

    Su, Hao; Shang, Weijian; Harrington, Kevin; Camilo, Alex; Cole, Gregory; Tokuda, Junichi; Hata, Nobuhiko; Tempany, Clare; Fischer, Gregory S.

    2012-02-01

    Magnetic resonance imaging (MRI) provides high resolution multi-parametric imaging, large soft tissue contrast, and interactive image updates making it an ideal modality for diagnosing prostate cancer and guiding surgical tools. Despite a substantial armamentarium of apparatuses and systems has been developed to assist surgical diagnosis and therapy for MRI-guided procedures over last decade, the unified method to develop high fidelity robotic systems in terms of accuracy, dynamic performance, size, robustness and modularity, to work inside close-bore MRI scanner still remains a challenge. In this work, we develop and evaluate an integrated modular hardware and software system to support the surgical workflow of intra-operative MRI, with percutaneous prostate intervention as an illustrative case. Specifically, the distinct apparatuses and methods include: 1) a robot controller system for precision closed loop control of piezoelectric motors, 2) a robot control interface software that connects the 3D Slicer navigation software and the robot controller to exchange robot commands and coordinates using the OpenIGTLink open network communication protocol, and 3) MRI scan plane alignment to the planned path and imaging of the needle as it is inserted into the target location. A preliminary experiment with ex-vivo phantom validates the system workflow, MRI-compatibility and shows that the robotic system has a better than 0.01mm positioning accuracy.

  13. Analysis of Access Control Policies in Operating Systems

    Science.gov (United States)

    Chen, Hong

    2009-01-01

    Operating systems rely heavily on access control mechanisms to achieve security goals and defend against remote and local attacks. The complexities of modern access control mechanisms and the scale of policy configurations are often overwhelming to system administrators and software developers. Therefore, mis-configurations are common, and the…

  14. Speed control system for an access gate

    Science.gov (United States)

    Bzorgi, Fariborz M.

    2012-03-20

    An access control apparatus for an access gate. The access gate typically has a rotator that is configured to rotate around a rotator axis at a first variable speed in a forward direction. The access control apparatus may include a transmission that typically has an input element that is operatively connected to the rotator. The input element is generally configured to rotate at an input speed that is proportional to the first variable speed. The transmission typically also has an output element that has an output speed that is higher than the input speed. The input element and the output element may rotate around a common transmission axis. A retardation mechanism may be employed. The retardation mechanism is typically configured to rotate around a retardation mechanism axis. Generally the retardation mechanism is operatively connected to the output element of the transmission and is configured to retard motion of the access gate in the forward direction when the first variable speed is above a control-limit speed. In many embodiments the transmission axis and the retardation mechanism axis are substantially co-axial. Some embodiments include a freewheel/catch mechanism that has an input connection that is operatively connected to the rotator. The input connection may be configured to engage an output connection when the rotator is rotated at the first variable speed in a forward direction and configured for substantially unrestricted rotation when the rotator is rotated in a reverse direction opposite the forward direction. The input element of the transmission is typically operatively connected to the output connection of the freewheel/catch mechanism.

  15. Is Your System Calibrated? MRI Gradient System Calibration for Pre-Clinical, High-Resolution Imaging

    OpenAIRE

    James O'Callaghan; Jack Wells; Simon Richardson; Holly Holmes; Yichao Yu; Simon Walker-Samuel; Bernard Siow; Lythgoe, Mark F

    2014-01-01

    High-field, pre-clinical MRI systems are widely used to characterise tissue structure and volume in small animals, using high resolution imaging. Both applications rely heavily on the consistent, accurate calibration of imaging gradients, yet such calibrations are typically only performed during maintenance sessions by equipment manufacturers, and potentially with acceptance limits that are inadequate for phenotyping. To overcome this difficulty, we present a protocol for gradient calibration...

  16. In-vivo human brain molecular imaging with a brain-dedicated PET/MRI system.

    Science.gov (United States)

    Cho, Zang Hee; Son, Young Don; Choi, Eun Jung; Kim, Hang Keun; Kim, Jeong Hee; Lee, Sang Yoon; Ogawa, Seiji; Kim, Young Bo

    2013-02-01

    Advances in the new-generation of ultra-high-resolution, brain-dedicated positron emission tomography-magnetic resonance imaging (PET/MRI) systems have begun to provide many interesting insights into the molecular dynamics of the brain. First, the finely delineated structural information from ultra-high-field MRI can help us to identify accurate landmark structures, thereby making it easier to locate PET activation sites that are anatomically well-correlated with metabolic or ligand-specific organs in the neural structures in the brain. This synergistic potential of PET/MRI imaging is discussed in terms of neuroscience and neurological research from both translational and basic research perspectives. Experimental results from the hippocampus, thalamus, and brainstem obtained with (18)F-fluorodeoxyglucose and (11)C-3-amino-4-(2-dimethylaminomethylphenylsulfanyl)benzonitrile are used to demonstrate the potential of this new brain PET/MRI system.

  17. A Nanocomplex System as Targeted Contrast Agent Delivery Vehicle for MRI Dynamic Contrast Enhancement Study

    OpenAIRE

    Korotcov, Alexandru; Shan, Liang; Meng, Huan; Wang, Tongxin; Sridhar, Rajagopalan; Zhao, Yuliang; Liang, Xing-Jie; Wang, Paul C.

    2010-01-01

    We have developed and tested a liposomal nanocomplex system, which contains Gd-DTPA as a payload and transferrin on the surface, as a tumor specific targeting MRI contrast agent for studying prostate cancer tumors in mice. In vivo, the probe significantly enhanced the MRI signal. The image contrast between the peripheral region of the tumor and the non-involved muscle was nearly 50% higher two hours after administration of the nanocomplex. The liposomal nanocomplex increased the amount of Gd ...

  18. Is your system calibrated? MRI gradient system calibration for pre-clinical, high-resolution imaging.

    Directory of Open Access Journals (Sweden)

    James O'Callaghan

    Full Text Available High-field, pre-clinical MRI systems are widely used to characterise tissue structure and volume in small animals, using high resolution imaging. Both applications rely heavily on the consistent, accurate calibration of imaging gradients, yet such calibrations are typically only performed during maintenance sessions by equipment manufacturers, and potentially with acceptance limits that are inadequate for phenotyping. To overcome this difficulty, we present a protocol for gradient calibration quality assurance testing, based on a 3D-printed, open source, structural phantom that can be customised to the dimensions of individual scanners and RF coils. In trials on a 9.4 T system, the gradient scaling errors were reduced by an order of magnitude, and displacements of greater than 100 µm, caused by gradient non-linearity, were corrected using a post-processing technique. The step-by-step protocol can be integrated into routine pre-clinical MRI quality assurance to measure and correct for these errors. We suggest that this type of quality assurance is essential for robust pre-clinical MRI experiments that rely on accurate imaging gradients, including small animal phenotyping and diffusion MR.

  19. Clinical evaluation of shoulder kinematic MRI using an open-type system

    International Nuclear Information System (INIS)

    Previous studies on kinematic MRI of the shoulder using cylindrical-type MRI systems were limited to internal or external rotation. The open-type MRI system enables kinematic MRI to be carried out for the abductive position, and is expected to permit evaluation of the superior and inferior glenoid labrum. It is important to evaluate the superior and inferior glenoid labrum in cases of sports injuries (baseball, tennis, etc.). We evaluated the superior and inferior glenoid labrum for abductive motion in asymptomatic healthy volunteers as a preliminary study. As the abduction angle increased, the superior labrum moved into the joint space. Its shape changed from round or triangular to crescent (p<0.0001), and there was increased signal for larger abduction angles (p<0.0001). On the other hand, the shape of the inferior labrum tended to change from crescent to triangular or round (p<0.0001). Increased signal was seen in the inferior labrum on about half the shoulders (N.P.). This did not change as the abduction angle increased. Our results define normal patterns for the superior and inferior glenoid labrum on abductive kinematic MRI in healthy volunteers. Abductive kinematic studies using an open-type MRI system, which permits dynamic evaluation of the superior and inferior glenoid labrum, are expected to be useful for various patients with sports injuries. (author)

  20. ACCESS: Design and Sub-System Performance

    Science.gov (United States)

    Kaiser, Mary Elizabeth; Morris, Matthew J.; McCandliss, Stephan R.; Rasucher, Bernard J.; Kimble, Randy A.; Kruk, Jeffrey W.; Pelton, Russell; Mott, D. Brent; Wen, Hiting; Foltz, Roger; Quijada, Manuel A.; Gum, Jeffery S.; Gardner, Jonathan P.; Kahle, Duncan M.; Benford, Dominic J.; Woodgate, Bruce E.; Wright, Edward L.; Feldman, Paul D.; Hart, Murdock; Moos, H. Warren; Reiss, Adam G.; Bohlin, Ralph; Deustua, Susana E.; Dixon, W. V.; Sahnow, David J.

    2012-01-01

    Establishing improved spectrophotometric standards is important for a broad range of missions and is relevant to many astrophysical problems. ACCESS, "Absolute Color Calibration Experiment for Standard Stars", is a series of rocket-borne sub-orbital missions and ground-based experiments designed to enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 -1.7 micrometer bandpass.

  1. Scheduling Heterogeneous Wireless Systems for Efficient Spectrum Access

    Directory of Open Access Journals (Sweden)

    Lichun Bao

    2010-01-01

    Full Text Available The spectrum scarcity problem emerged in recent years, due to unbalanced utilization of RF (radio frequency bands in the current state of wireless spectrum allocations. Spectrum access scheduling addresses challenges arising from spectrum sharing by interleaving the channel access among multiple wireless systems in a TDMA fashion. Different from cognitive radio approaches which are opportunistic and noncollaborative in general, spectrum access scheduling proactively structures and interleaves the channel access pattern of heterogeneous wireless systems, using collaborative designs by implementing a crucial architectural component—the base stations on software defined radios (SDRs. We discuss our system design choices for spectrum sharing from multiple perspectives and then present the mechanisms for spectrum sharing and coexistence of GPRS+WiMAX and GPRS+WiFi as use cases, respectively. Simulations were carried out to prove that spectrum access scheduling is an alternative, feasible, and promising approach to the spectrum scarcity problem.

  2. Task Delegation Based Access Control Models for Workflow Systems

    Science.gov (United States)

    Gaaloul, Khaled; Charoy, François

    e-Government organisations are facilitated and conducted using workflow management systems. Role-based access control (RBAC) is recognised as an efficient access control model for large organisations. The application of RBAC in workflow systems cannot, however, grant permissions to users dynamically while business processes are being executed. We currently observe a move away from predefined strict workflow modelling towards approaches supporting flexibility on the organisational level. One specific approach is that of task delegation. Task delegation is a mechanism that supports organisational flexibility, and ensures delegation of authority in access control systems. In this paper, we propose a Task-oriented Access Control (TAC) model based on RBAC to address these requirements. We aim to reason about task from organisational perspectives and resources perspectives to analyse and specify authorisation constraints. Moreover, we present a fine grained access control protocol to support delegation based on the TAC model.

  3. Disability standards and guidelines for learning management systems: Evaluating accessibility

    OpenAIRE

    Moreno, Lourdes; Iglesias, Ana; Calvo, Rocío; Delgado, Sandra; Zaragoza, Luis

    2012-01-01

    Currently, the great majority of institutions of higher education use Learning Content Management Systems (LCMSs) and Learning Management Systems (LMS) as pedagogical tools. In order to make these systems accessible to all students, it is important to take into account not only educational standards, but also standards of accessibility. It is essential to have with procedures and well-established method for evaluating these tools, so in this paper we propose a method for evaluatin...

  4. The role of diffusion-weighted echo planar MRI in central nervous system infections regarding etiopathogeneses.

    Science.gov (United States)

    Kıroğlu, Yılmaz; Karabulut, Nevzat; Alkan, Alpay

    2010-12-01

    Neuroimaging constitutes an important component in the diagnosis of the underlying infectious agents in central nervous system (CNS) infections. Despite the recent advances in neuroimaging evaluation, the diagnosis of unclear infectious CNS diseases remains a challenge. Conventional magnetic resonance imaging (MRI) is used in routine practice to identify abnormal areas involved in CNS infections. More recent MRI techniques, such as diffusion-weighted imaging (DWI), provide additional helpful information in the assessment of CNS infectious lesions compared with conventional MRI. This pictorial essay summarizes the clinical role of DWI in the demonstration of CNS infections including meningitis, encephalitis and pyogenic infections, and determination of the lesions compared with conventional MRI on the basis of physiopathologic phases of the infections.

  5. Time division multiplexed orbital angular momentum access system

    Science.gov (United States)

    Shi, Jianyang; Fang, Yuan; Chi, Nan

    2016-03-01

    We propose and experimentally demonstrate time division multiplexed orbital angular momentum (OAM) access system to increase transmission capacity and spectral efficiency. In this system, data carried on different time tributaries share the same OAM mode. Multiple time division multiplexed OAM modes are multiplexed to realize two-dimensional (time dimension and OAM dimension) multiplexing. Therefore, the capacity and spectral efficiency of the access system will increase. The orthogonality between optical time division multiplexing (OTDM) and OAM techniques is also verified in our experiment. In a proof-of-concept experiment, 2×5-Gbps return-to-zero signal over OAM mode +4 is transmitted and investigated. The bit error ratio performance after transmission in this system can be smaller than 1×10-9. Results show that the proposed time division multiplexed OAM access system is suitable for future broadband access network.

  6. Evaluation of Brain and Cervical MRI Abnormality Rates in Patients With Systemic Lupus Erythematosus With or Without Neurological Manifestations

    International Nuclear Information System (INIS)

    Central nervous system (CNS) involvement has been observed in 14-80% of patients with systemic lupus erythematosus (SLE). Magnetic resonance imaging (MRI) is an appropriate method for evaluating CNS involvement in these patients. Clinical manifestations and MRI findings of CNS lupus should be differentiated from other mimicking diseases such as multiple sclerosis (MS). The aim of this study was to evaluate the prevalence and extent of brain and cervical cord MRI lesions of lupus patients. The relationship between neurological signs and symptoms and MRI findings were evaluated as well. Fifty SLE patients who had been referred to the rheumatology clinic of our hospital within 2009 were included in a cross sectional study. All patients fulfilled the revised 1981 American College of Rheumatology (ACR) criteria for SLE. We evaluated the neurological signs and symptoms and brain and cervical MRI findings in these patients. Forty-one patients (82%) were female and nine (18%) were male. The mean age was 30.1 ± 9.3 years. Twenty eight (56%) patients had an abnormal brain MRI. No one showed any abnormality in the cervical MRI. The lesions in 20 patients were similar to demyelinative plaques. Seventeen patients with abnormal brain MRI were neurologically asymptomatic. There was only a significant relationship between neurological motor manifestations and brain MRI abnormal findings. Unlike the brain, cervical MRI abnormality and especially asymptomatic cord involvement in MRI is quite rare in SLE patients. This finding may be helpful to differentiate SLE from other CNS disorders such as MS

  7. MULTIAGENT SYSTEM BASED ON GENETIC ACCESS MATRIX ANALYSIS

    Directory of Open Access Journals (Sweden)

    Noto Masato

    2012-12-01

    Full Text Available How should an individual contribute to the public good? Conversely, how does the public help the individual? We should analyze and alleviate conflicts in community clouds. Covert channels in the access matrix are caused by conflicts between public values and a private sense of values. We cannot control the information leaks from the covert channels by using only access control. We believe that the community cloud system should emphasize harmony between public values and a private sense of values. We interpret the access matrix as follows: The acts of the individual are generalized and symbolized by an access matrix that describes the access operations of the subject. We propose a multiagent system embodying the concept of swarm intelligence to analyze the covert channels that arise. Each agent has a group target and an individual target. The group target and an individual target include targets for generation of access and restriction of access. The system does not have any principle of universal control. Instead, an agent’s interactions are guided by metaheuristics for achieving targets. The social order of the whole society is made from the agents’ interactions related to the group value target, group game target, an individual value target, and an individual game target. The conceptual framework and multiagent system presented here are intended to support people. If the covert channel problem can be solved, it will become possible for people to use community clouds safely.

  8. The implementation of wireless access in EPON system

    Science.gov (United States)

    Chang, Yuguang; Liu, Deming; Wu, Guangsheng

    2008-11-01

    Ethernet Passive Optical Network(EPON) is one of the most promising fibre-based access techniques which has been more and more widely used in today's access networks. In this paper, we proposed to integrate WLAN technology with EPON to provide wireless service in EPON network. First of all, theoretical analysis is given to support the feasibility of integrating WLAN technology into EPON system. Then, the architecture of the integrated system is descried. The key point of the plan is that an integrated ONU and WLAN BS called ONU-WLAN AP is setup in the system instead of a standard ONU. This is also the main difference between proposed system and a normal EPON system. The ONU-WLAN AP can provide both wired access and wireless access to the end users. System design and implementation is discussed in the following paragraph. Transmission experiments and results of the proposed plan are also described in this paper. The experimental results show that the average traffic throughput of the system could reach to approximate 20Mbps. Finally, conclusions are drawn out: The proposed system can work properly. The integrated system could be a costeffective plan for broadband access network.

  9. An optically coupled system for quantitative monitoring of MRI gradient currents induced into endocardial leads.

    Science.gov (United States)

    Mattei, E; Calcagnini, G; Triventi, M; Delogu, A; Del Guercio, M; Angeloni, A; Bartolini, P

    2013-01-01

    The time-varying gradient fields generated during Magnetic Resonance Imaging (MRI) procedures have the potential to induce electrical current on implanted endocardial leads. Whether this current can result in undesired cardiac stimulation is unknown. This paper presents an optically coupled system with the potential to quantitatively measure the currents induced by the gradient fields into endocardial leads during MRI procedures. Our system is based on a microcontroller that works as analog-to-digital (A/D) converter and sends the current signal acquired from the lead to an optical high-speed light-emitting-diode transmitter. Plastic fiber guides the light outside the MRI chamber, to a photodiode receiver and then to an acquisition board connected to a PC. The preliminary characterization of the performances of the system is also presented. PMID:24110209

  10. Personnel Access Control System Evaluation for National Ignition Facility Operations

    Energy Technology Data Exchange (ETDEWEB)

    Altenbach, T; Brereton, S.; Hermes, G.; Singh, M.

    2001-06-01

    The purpose of this document is to analyze the baseline Access Control System for the National Ignition Facility (NIF), and to assess its effectiveness at controlling access to hazardous locations during full NIF operations. It reviews the various hazards present during a NIF shot sequence, and evaluates the effectiveness of the applicable set of controls at preventing access while the hazards are present. It considers only those hazards that could potentially be lethal. In addition, various types of technologies that might be applicable at NIF are reviewed, as are systems currently in use at other facilities requiring access control for safety reasons. Recommendations on how this system might be modified to reduce risk are made.

  11. Channel Access Algorithm Design for Automatic Identification System

    Institute of Scientific and Technical Information of China (English)

    Oh Sang-heon; Kim Seung-pum; Hwang Dong-hwan; Park Chan-sik; Lee Sang-jeong

    2003-01-01

    The Automatic Identification System (AIS) is a maritime equipment to allow an efficient exchange of the navigational data between ships and between ships and shore stations. It utilizes a channel access algorithm which can quickly resolve conflicts without any intervention from control stations. In this paper, a design of channel access algorithm for the AIS is presented. The input/output relationship of each access algorithm module is defined by drawing the state transition diagram, dataflow diagram and flowchart based on the technical standard, ITU-R M.1371. In order to verify the designed channel access algorithm, the simulator was developed using the C/C++ programming language. The results show that the proposed channel access algorithm can properly allocate transmission slots and meet the operational performance requirements specified by the technical standard.

  12. Flagellated Magnetotactic Bacteria as Controlled MRI-trackable Propulsion and Steering Systems for Medical Nanorobots Operating in the Human Microvasculature.

    Science.gov (United States)

    Martel, Sylvain; Mohammadi, Mahmood; Felfoul, Ouajdi; Lu, Zhao; Pouponneau, Pierre

    2009-04-01

    Although nanorobots may play critical roles for many applications in the human body such as targeting tumoral lesions for therapeutic purposes, miniaturization of the power source with an effective onboard controllable propulsion and steering system have prevented the implementation of such mobile robots. Here, we show that the flagellated nanomotors combined with the nanometer-sized magnetosomes of a single Magnetotactic Bacterium (MTB) can be used as an effective integrated propulsion and steering system for devices such as nanorobots designed for targeting locations only accessible through the smallest capillaries in humans while being visible for tracking and monitoring purposes using modern medical imaging modalities such as Magnetic Resonance Imaging (MRI). Through directional and magnetic field intensities, the displacement speeds, directions, and behaviors of swarms of these bacterial actuators can be controlled from an external computer.

  13. Abnormal findings of magnetic resonance imaging (MRI) in patients with systemic lupus erythematosus involving the brain

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Akira; Okada, Jun; Kondo, Hirobumi (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine); Kashiwazaki, Sadao

    1992-06-01

    To elucidate the clinical significance of MRI on central nervous system systemic lupus erythematosus (CNS-SLE), MRI and CT scans were performed in 35 patients with SLE, of 18 patients who had CNS manifestations at the time of MRI examinations. The investigations were also carried out in 17 patients without CNS-SLE. The rate of detection of abnormal findings on MRI in patients with CNS-SLE was 77.2% (14/18), which was high, as compared with the rate of those on CT scans (50%: 9/18). Especially, all of 4 patients with seizure and 3 patients with encephalopathy showed abnormal MRI findings, although respectively 50% and 33.3% of them had abnormal CT scan findings. MRI findings were classified into 4 groups below: (1) Large focal are as increased signal intensity at T2 weighted image. These were observed in 2 of 4 patients with seizure and 1 of 3 patients with encephalopathy, which were completely resolved after treatment. (2) Patchy subcortical foci of increased signal intensity at T2 weighted image. These were observed in 11 of 18 CNS-SLE and 7 of 17 without CNS-SLE, which were not detected by CT scan. (3) All of six patients with cerebral infarctions showed high signal intensity areas at T2 weighted image and low signal intensity areas at T1 weighted image. (4) Normal findings were observed in 4 of 18 CNS-SLE (22.2%). We concluded that MRI is useful for the evaluation of CNS-SLE and provides more information than CT scan. (author).

  14. A mobile console for local access to accelerator control systems.

    CERN Multimedia

    1981-01-01

    Microprocessors were installed as auxiliary crate controllers (ACCs) in the CAMAC interface of control systems for various accelerators. The same ACC was also at the hearth of a stand-alone system in the form of a mobile console. This was also used for local access to the control systems for tests and development work (Annual Report 1981, p. 80, Fig. 10).

  15. Immediate data access system for LHD experiments

    International Nuclear Information System (INIS)

    Several kinds of computer systems are used to perform large helical device (LHD) experiments, and each produces its own data format. Therefore, it has been difficult to deal with these data simultaneously. In order to solve this problem, the Kaiseki server was developed; it has been facilitating the unified retrieval of LHD data. The data acquired or analyzed by various computer systems are converted into the unified ASCII format, or Kaiseki format, and transferred to the Kaiseki server. With this method, the researchers can visualize and analyze the data produced by various kinds of computers in the same way. Because validations are needed before registering on the Kaiseki server, it takes time to make the validated data available. However, some researchers need data as soon as it is gathered in order to adjust their instruments during the experiments. To satisfy this requirement, a new visualization system has been under development. The new system has two ways to visualize the data as physical values from the raw data. If the conversion task is not complex, the NIFSscope, a visualization tool, converts the raw data into physics data by itself. If the task is too complex to handle, it asks the ANACalc server to make physics data. When the ANACalc server receives a request, it delegates calculation programs to convert the acquired data into physics data. Because the interfaces between the server and the calculation processes are independent of programming languages and operating systems, the calculation processes can be placed on different computers and the server load can be reduced. Therefore, the system can respond to changes in requirements by replacing the calculation programs, and can easily be expanded by increasing the number of calculation servers

  16. Heart MRI

    Science.gov (United States)

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  17. Role Based Access Control System in the ATLAS Experiment

    CERN Document Server

    Valsan, M L; The ATLAS collaboration; Lehmann Miotto, G; Scannicchio, D A; Schlenker, S; Filimonov, V; Khomoutnikov, V; Dumitru, I; Zaytsev, A S; Korol, A A; Bogdantchikov, A; Avolio, G; Caramarcu, C; Ballestrero, S; Darlea, G L; Twomey, M; Bujor, F

    2010-01-01

    The complexity of the ATLAS experiment motivated the deployment of an integrated Access Control System in order to guarantee safe and optimal access for a large number of users to the various software and hardware resources. Such an integrated system was foreseen since the design of the infrastructure and is now central to the operations model. In order to cope with the ever growing needs of restricting access to all resources used within the experiment, the Roles Based Access Control (RBAC) previously developed has been extended and improved. The paper starts with a short presentation of the RBAC design, implementation and the changes made to the system to allow the management and usage of roles to control access to the vast and diverse set of resources. The paper continues with a detailed description of the integration across all areas of the system: local Linux and Windows nodes in the ATLAS Control Network (ATCN), the Linux application gateways offering remote access inside ATCN, the Windows Terminal Serv...

  18. Role Based Access Control system in the ATLAS experiment

    CERN Document Server

    Valsan, M L; The ATLAS collaboration; Lehmann Miotto, G; Scannicchio, D A; Schlenker, S; Filimonov, V; Khomoutnikov, V; Dumitru, I; Zaytsev, A S; Korol, A A; Bogdantchikov, A; Caramarcu, C; Ballestrero, S; Darlea, G L; Twomey, M; Bujor, F; Avolio, G

    2011-01-01

    The complexity of the ATLAS experiment motivated the deployment of an integrated Access Control System in order to guarantee safe and optimal access for a large number of users to the various software and hardware resources. Such an integrated system was foreseen since the design of the infrastructure and is now central to the operations model. In order to cope with the ever growing needs of restricting access to all resources used within the experiment, the Roles Based Access Control (RBAC) previously developed has been extended and improved. The paper starts with a short presentation of the RBAC design, implementation and the changes made to the system to allow the management and usage of roles to control access to the vast and diverse set of resources. The paper continues with a detailed description of the integration across all areas of the system: local Linux and Windows nodes in the ATLAS Control Network (ATCN), the Linux application gateways offering remote access inside ATCN, the Windows Terminal Serv...

  19. The Romanian Banking System after EU Accession

    Directory of Open Access Journals (Sweden)

    Viorica IOAN

    2011-11-01

    Full Text Available Banks play an important role in the financial sector, in the proper functioning of economic entities and in the economy as a whole, therefore over time the establishment of a functioning banking system capable of delivering a wide range of products and services to meet the requirements of all potential customers has been a permanent concern. Considering the economic and financial reality, both internationally and domestically, each country and therefore, Romania is interested in creating a solid banking system, enabling the appropriate organizational framework in order to ensure a development of the financial mechanisms. The banking system as the basic element of the financial system, allows an efficient allocation of resources in the economy and, in order to function properly, we need to know the risks they face:a slow economic growth may cause losses due to difficulties in repaying bank loans, due to lower sales or lower wages, changes in asset prices may cause financial losses to investors, decreasing a sector of the economy which has monopolized the banks’ and investors’ attention.

  20. Application Of Fuzzy System In Segmentation Of MRI Brain Tumor

    CERN Document Server

    Rajya, Mrigank; Sheoran, Swati

    2010-01-01

    Segmentation of images holds an important position in the area of image processing. It becomes more important whi le typically dealing with medical images where presurgery and post surgery decisions are required for the purpose of initiating and speeding up the recovery process. Segmentation of 3-D tumor structures from magnetic resonance images (MRI) is a very challenging problem due to the variability of tumor geometry and intensity patterns. Level set evolution combining global smoothness with the flexibility of topology changes offers significant advantages over the conventional statistical classification followed by mathematical morphology. Level set evolution with constant propagation needs to be initialized either completely inside or outside the tumor and can leak through weak or missing boundary parts. Replacing the constant propagation term by a statistical force overcomes these limitations and results in a convergence to a stable solution. Using MR images presenting tumors, probabilities for backgr...

  1. Efficient medium access control protocol for geostationary satellite systems

    Institute of Scientific and Technical Information of China (English)

    王丽娜; 顾学迈

    2004-01-01

    This paper proposes an efficient medium access control (MAC) protocol based on multifrequency-time division multiple access (MF-TDMA) for geostationary satellite systems deploying multiple spot-beams and onboard processing,which uses a method of random reservation access with movable boundaries to dynamically request the transmission slots and can transmit different types of traffic. The simulation results have shown that our designed MAC protocol can achieve a high bandwidth utilization, while providing the required quality of service (QoS) for each class of service.

  2. A new access control system by fingerprint for radioisotope facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Hiroko; Hirata, Yasuki [Kyushu Univ., Fukuoka (Japan). Radioisotope Center; Kondo, Takahiro; Takatsuki, Katsuhiro

    1998-04-01

    We applied a new fingerprint checker for complete access control to the radiation controlled area and to the radioisotope storage room, and prepared softwares for the best use of this checker. This system consists of a personal computer, access controllers, a fingerprint register, fingerprint checkers, a tenkey and mat sensors, permits ten thousand users to register their fingerprints and its hard disk to keep more than a million records of user`s access. Only 1% of users could not register their fingerprints worn-out, registered four numbers for a fingerprint. The softwares automatically provide varieties of reports, caused a large reduction in manual works. (author)

  3. MRI compatible small animal monitoring and trigger system for whole body scanners

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Karl-Heinz; Krumbein, Ines; Reichenbach, Juergen R. [Jena University Hospital (Germany). Medical Physics Group; Pfeiffer, Norman [Jena University Hospital (Germany). Medical Physics Group; Ernst-Abbe-Fachhochschule Jena (Germany); Herrmann, Lutz [Ernst-Abbe-Fachhochschule Jena (Germany)

    2014-03-01

    Performing magnetic resonance imaging (MRI) experiments with small animals requires continuous monitoring of vital parameters, especially the respiration rate. Clinical whole-body MR scanners represent an attractive option for preclinical imaging as dedicated animal scanners are cost-intensive in both investment and maintenance, thus limiting their availability. Even though impressive image quality is achievable with clinical MR systems in combination with special coils, their built-in physiologic monitoring and triggering units are often not suited for small animal imaging. In this work, we present a simple, MRI compatible low cost solution to monitor the respiration and heart rate of small animals in a clinical whole-body MR scanner. The recording and processing of the biosignals as well as the optimisation of the respiratory trigger generation is described. Additionally rat and mouse in-vivo MRI experiments are presented to illustrate the effectiveness of the monitoring and respiratory trigger system in suppressing motion artifacts. (orig.)

  4. MRI compatible small animal monitoring and trigger system for whole body scanners

    International Nuclear Information System (INIS)

    Performing magnetic resonance imaging (MRI) experiments with small animals requires continuous monitoring of vital parameters, especially the respiration rate. Clinical whole-body MR scanners represent an attractive option for preclinical imaging as dedicated animal scanners are cost-intensive in both investment and maintenance, thus limiting their availability. Even though impressive image quality is achievable with clinical MR systems in combination with special coils, their built-in physiologic monitoring and triggering units are often not suited for small animal imaging. In this work, we present a simple, MRI compatible low cost solution to monitor the respiration and heart rate of small animals in a clinical whole-body MR scanner. The recording and processing of the biosignals as well as the optimisation of the respiratory trigger generation is described. Additionally rat and mouse in-vivo MRI experiments are presented to illustrate the effectiveness of the monitoring and respiratory trigger system in suppressing motion artifacts. (orig.)

  5. Development of a flexible optical fiber based high resolution integrated PET/MRI system

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi; Watabe, Hiroshi; Kanai, Yasukazu; Watabe, Tadashi; Aoki, Masaaki; Sugiyama, Eiji; Kato, Katsuhiko; Hatazawa, Jun [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi 461-8673 (Japan); Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan); Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, 565-0871 Osaka (Japan); Neomax Engineering, Takasaki 370-2115 (Japan); Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya 461-8673 (Japan); Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan) and Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan)

    2012-11-15

    Purpose: The simultaneous measurement of PET and magnetic resonance imaging (MRI) is an emerging field for molecular imaging research. Although optical fiber based PET/MRI systems have advantages on less interference between PET and MRI, there is a drawback in reducing the scintillation light due to the fiber. To reduce the problem, the authors newly developed flexible optical fiber bundle based block detectors and employed them for a high resolution integrated PET/MRI system. Methods: The flexible optical fiber bundle used 0.5 mm diameter, 80 cm long double clad fibers which have dual 12 mm Multiplication-Sign 24 mm rectangular inputs and a single 24 mm Multiplication-Sign 24 mm rectangular output. In the input surface, LGSO scintillators of 0.025 mol.% (decay time: {approx}31 ns: 0.9 mm Multiplication-Sign 1.3 mm Multiplication-Sign 5 mm) and 0.75 mol.% (decay time: {approx}46 ns: 0.9 mm Multiplication-Sign 1.3 mm Multiplication-Sign 6 mm) were optically coupled in depth direction to form depth-of-interaction detector, arranged in 11 Multiplication-Sign 13 matrix and optically coupled to the fiber bundle. The two inputs of the bundle are bent for 90 Degree-Sign , bound to one, and are optically coupled to a Hamamatsu 1-in. square position sensitive photomultiplier tube. Results: Light loss due to the fiber bundle could be reduced and the performance of the block detectors was improved. Eight optical fiber based block detectors (16 LGSO blocks) were arranged in a 56 mm diameter ring to form a PET system. Spatial resolution and sensitivity were 1.2 mm full-width at half-maximum and 1.2% at the central field-of-view, respectively. Sensitivity change was less than 1% for 2 Degree-Sign C temperature changes. This PET system was integrated with a 0.3 T permanent magnet MRI system which has 17 cm diameter hole at the yoke area for insertion of the PET detector ring. There was no observable interference between PET and MRI. Simultaneous imaging of PET and MRI was

  6. The OMERACT psoriatic arthritis magnetic resonance imaging scoring system (PsAMRIS): definitions of key pathologies, suggested MRI sequences, and preliminary scoring system for PsA Hands

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; McQueen, Fiona; Wiell, Charlotte;

    2009-01-01

    This article describes a preliminary OMERACT psoriatic arthritis magnetic resonance image scoring system (PsAMRIS) for evaluation of inflammatory and destructive changes in PsA hands, which was developed by the international OMERACT MRI in inflammatory arthritis group. MRI definitions of importan...... pathologies in peripheral PsA and suggestions concerning appropriate MRI sequences for use in PsA hands are also provided.......This article describes a preliminary OMERACT psoriatic arthritis magnetic resonance image scoring system (PsAMRIS) for evaluation of inflammatory and destructive changes in PsA hands, which was developed by the international OMERACT MRI in inflammatory arthritis group. MRI definitions of important...

  7. Impact of breast MRI on surgical treatment, axillary approach, and systemic therapy for breast cancer.

    Science.gov (United States)

    Mameri, Claudia S; Kemp, Claudio; Goldman, Suzan M; Sobral, Luiz A; Ajzen, Sergio

    2008-01-01

    The purpose of this study is to determine how often breast magnetic resonance imaging (MRI) brings additional information that influences management of patients with breast cancer concerning surgical treatment, axillary lymph node approach, and systemic therapy. From July 2004 to July 2005, 99 patients recently diagnosed with breast cancer in clinical stages 0, I, and II were prospectively evaluated about their therapeutic plans, at first based on usual protocol (physical examination, mammography and ultrasound) and next going through bilateral breast MR. Examinations were carried out at 1.5 T on five sequences of FSPGR 3D for 90 seconds (four post-gadolinium diethylenetriaminepenta acetic acid 0.16 mM/Kg). Parameters analyzed on MRI were extension of primary lesion; detection of multifocality, multicentricity, or contra lateral lesion; muscular or skin involvement; and presence of lymph node involvement. Pathologic confirmation of additional lesions was achieved by core or excisional biopsy. MRI made 69 additional findings in 53 patients. Fifty-one findings were true-positives (51/69 = 73.9%) including 16 larger single lesions; 18 cases of multifocality; 7 cases of multicentricity; 3 cases of contra lateral lesion; 5 cases of lymph node involvement (one of them involved medial thoracic chain); 1 with muscular involvement; 1 with skin involvement. MRI has changed previous management plans in 44.4% of 99 patients. We observed increase in mastectomies (26.8%) on axillary lymph node dissection (25%) and changes on systemic therapy (20.2%), all because of additional MRI true-positive findings. Breast MRI alters significantly the rate of mastectomy, the approach of axillary chain for staging, and the use of systemic therapy because of its accuracy in evaluating breast cancer local extent. PMID:18476882

  8. Portable MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle A. [Los Alamos National Laboratory

    2012-06-29

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  9. Value of MRI of the brain in patients with systemic lupus erythematosus and neurologic disturbance

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, J.E.; Sundgren, P.C.; Maly, P. [Division of Neuroradiology, Department of Radiology, University of Michigan, 1500 East Medical Center Drive, MI 48109, Ann Arbor (United States); Attwood, J.; McCune, J. [Department of Internal Medicine, University of Michigan, 1500 East Medical Center Drive, MI 48109, Ann Arbor (United States)

    2004-01-01

    Our objective was to review the frequency and pattern of signal abnormalities seen on conventional MRI in patients with suspected neuropsychiatric systemic lupus erythematosus (NP-SLE). We reviewed 116 MRI examinations of the brain performed on 85 patients with SLE, (81 women, four men, aged 21-78 years, mean 40.6 years) presenting with neurological disturbances. MRI was normal or nearly normal in 34%. In 60% high-signal lesions were observed on T2-weighted images, frequently in the frontal and parietal subcortical white matter. Infarct-like lesions involving gray and white matter were demonstrated in 21 of cases. Areas of restricted diffusion were seen in 12 of the 67 patients who underwent diffusion-weighted imaging. Other abnormalities included loss of brain volume, hemorrhage, meningeal enhancement, and bilateral high signal in occipital white-matter. The MRI findings alone did not allow us to distinguish between thromboembolic and inflammatory events in many patients. Some patients with normal MRI improved clinically while on immunosuppressive therapy. More sensitive and/or specific imaging methods, such as spectroscopy and perfusion-weighted imaging, should be investigated in these subgroups of patients with suspected NP-SLE. (orig.)

  10. Embedded Systems Programming: Accessing Databases from Esterel

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available A current limitation in embedded controller design and programming is the lack of database support in development tools such as Esterel Studio. This article proposes a way of integrating databases and Esterel by providing two application programming interfaces (APIs which enable the use of relational databases inside Esterel programs. As databases and Esterel programs are often executed on different machines, result sets returned as responses to database queries may be processed either locally and according to Esterel’s synchrony hypothesis, or remotely along several of Esterel’s execution cycles. These different scenarios are reflected in the design and usage rules of the two APIs presented in this article, which rely on Esterel’s facilities for extending the language by external data types, external functions, and procedures, as well as tasks. The APIs’ utility is demonstrated by means of a case study modelling an automated warehouse storage system, which is constructed using Lego Mindstorms robotics kits. The robot’s controller is programmed in Esterel in a way that takes dynamic ordering information and the warehouse’s floor layout into account, both of which are stored in a MySQL database.

  11. Embedded Systems Programming: Accessing Databases from Esterel

    Directory of Open Access Journals (Sweden)

    White David

    2008-01-01

    Full Text Available Abstract A current limitation in embedded controller design and programming is the lack of database support in development tools such as Esterel Studio. This article proposes a way of integrating databases and Esterel by providing two application programming interfaces (APIs which enable the use of relational databases inside Esterel programs. As databases and Esterel programs are often executed on different machines, result sets returned as responses to database queries may be processed either locally and according to Esterel's synchrony hypothesis, or remotely along several of Esterel's execution cycles. These different scenarios are reflected in the design and usage rules of the two APIs presented in this article, which rely on Esterel's facilities for extending the language by external data types, external functions, and procedures, as well as tasks. The APIs' utility is demonstrated by means of a case study modelling an automated warehouse storage system, which is constructed using Lego Mindstorms robotics kits. The robot's controller is programmed in Esterel in a way that takes dynamic ordering information and the warehouse's floor layout into account, both of which are stored in a MySQL database.

  12. Robot-assisted needle placement in open MRI: system architecture, integration and validation.

    Science.gov (United States)

    DiMaio, S P; Pieper, S; Chinzei, K; Hata, N; Haker, S J; Kacher, D F; Fichtinger, G; Tempany, C M; Kikinis, R

    2007-01-01

    In prostate cancer treatment, there is a move toward targeted interventions for biopsy and therapy, which has precipitated the need for precise image-guided methods for needle placement. This paper describes an integrated system for planning and performing percutaneous procedures with robotic assistance under MRI guidance. A graphical planning interface allows the physician to specify the set of desired needle trajectories, based on anatomical structures and lesions observed in the patient's registered pre-operative and pre-procedural MR images, immediately prior to the intervention in an open-bore MRI scanner. All image-space coordinates are automatically computed, and are used to position a needle guide by means of an MRI-compatible robotic manipulator, thus avoiding the limitations of the traditional fixed needle template. Automatic alignment of real-time intra-operative images aids visualization of the needle as it is manually inserted through the guide. Results from in-scanner phantom experiments are provided. PMID:17364655

  13. Public key based uniform access framework in 3G systems

    Institute of Scientific and Technical Information of China (English)

    WANG Yi; GU Da-wu; BAI Ying-cai

    2006-01-01

    This paper compares two types of access methods in 3G telecommunication systems, registration based access method and alternative access method. Through analyzing their common ground, we establish a public-key based uniform access framework, which combines different access methods into one unified model and provides more scalability and flexibility. Then an improved wireless authentication protocol is introduced into the framework, which gives an example of how unification is obtained by using public key technology. Since original protocol has flaws, an improved one is proposed based on security investigation. Improved authentication protocol overcomes the weakness of the original one, and maintains all the security features owned by old protocol. Finally, the feasibility of this framework is analyzed with consideration of current development in mobile telecommunication fields and the future trend of 3G systems. The result shows that public key technology has a promising future in 3G and Beyond 3G systems. It points out a new way for key management in future telecommunication systems.

  14. Advances of blood oxygen-level dependent MRI in muscular system

    International Nuclear Information System (INIS)

    BOLD-fMRI has been applied to muscular system to observe muscular pathophysiological change after performing a task and show the characteristics of muscle perfusion. This paper mainly introduces the scanning sequence, common tasking methods, such as cuff compression, excise, oxygen and drug, etc. It also introduces clinical study of perfusion reserve of muscular tissue with abnormal blood vessels. (authors)

  15. Magnetic field homogeneity of birdcage coil for 4T MRI system with no lumped circuit elements

    International Nuclear Information System (INIS)

    In recent years, magnetic resonance imaging (MRI) systems that operate up to under 3T are being used in clinical practice in Japan. In order to achieve the requirements of higher image quality and shorter imaging times, devices that utilize high magnetic fields (> 3T) and high power electromagnetic (EM) wave pulses have been developed. The rise of the static magnetic field is proportional to the increase of the EM wave frequency which raises the issue of variation in capacitance used in the radio frequency (RF) coil for MRI system. In addition, increasing power causes problems of withstanding voltage and these approaches leads to generation of non-uniform magnetic field inside the RF coil. Therefore, we proposed a birdcage coil without the use of lumped circuit elements for MRI systems in previous study. However, it is difficult to fabricate this birdcage coil. Hence, simply-structured birdcage coil with no lumped circuit elements is desired. In this paper, we propose a simply-structured birdcage coil with no lumped circuit elements for a 4T MRI system. In addition, the authors investigated the input impedance and magnetic field distribution of the proposed coil by FDTD calculations and measurements. The results confirm that the proposed birdcage coil matches the performance of the conventional birdcage coil which includes several capacitors. (author)

  16. Cost Effective Open Geometry HTS MRI System amended to BSCCO 2212 Wire for High Field Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Kennth Marken

    2006-08-11

    The original goal of this Phase II Superconductivity Partnership Initiative project was to build and operate a prototype Magnetic Resonance Imaging (MRI) system using high temperature superconductor (HTS) coils wound from continuously processed dip-coated BSCCO 2212 tape conductor. Using dip-coated tape, the plan was for MRI magnet coils to be wound to fit an established commercial open geometry, 0.2 Tesla permanent magnet system. New electronics and imaging software for a prototype higher field superconducting system would have added significantly to the cost. However, the use of the 0.2 T platform would allow the technical feasibility and the cost issues for HTS systems to be fully established. Also it would establish the energy efficiency and savings of HTS open MRI compared with resistive and permanent magnet systems. The commercial goal was an open geometry HTS MRI running at 0.5 T and 20 K. This low field open magnet was using resistive normal metal conductor and its heat loss was rather high around 15 kolwatts. It was expected that an HTS magnet would dissipate around 1 watt, significantly reduce power consumption. The SPI team assembled to achieve this goal was led by Oxford Instruments, Superconducting Technology (OST), who developed the method of producing commercial dip coated tape. Superconductive Components Inc. (SCI), a leading US supplier of HTS powders, supported the conductor optimization through powder optimization, scaling, and cost reduction. Oxford Magnet Technology (OMT), a joint venture between Oxford Instruments and Siemens and the world’s leading supplier of MRI magnet systems, was involved to design and build the HTS MRI magnet and cryogenics. Siemens Magnetic Resonance Division, a leading developer and supplier of complete MRI imaging systems, was expected to integrate the final system and perform imaging trials. The original MRI demonstration project was ended in July 2004 by mutual consent of Oxford Instruments and Siemens. Between

  17. Improving information access with an emergency department system.

    OpenAIRE

    Travers, D.; Parham, T.

    1997-01-01

    An emergency department (ED) clinical system was developed by in-house personnel, with ED physician, nursing, registration and clerical staff input. The utilization of existing hardware and customization of the hospital's mainframe hospital information system (HIS) facilitated the implementation of a cost-effective system that meets the information access needs of a busy, state-of-the-art academic ED. The transition to automation of the ED was facilitated through the use of a comprehensive tr...

  18. Accessibility and Radioactivity Calculations for Nuclear Reactor Shutdown System

    International Nuclear Information System (INIS)

    An important consideration in the design of power reactors is providing access to the reactor cooling system for the purposes of maintenance, repair and refuelling. The major sources of radiation which tend to prohibit such access are: induced activity of the reactor coolant, activated impurities in the reactor coolant and radiation originating in the reactor core both during reactor operation and after shut down. Impurities in the reactor coolant may be present in high enough concentrations so that their activation restricts accessibility for maintenance after shutdown. When water being used as a coolant, the activity of the water itself is very short- lived but their corrosive nature, resultant high impurity and induced activity of structural material are the major source of activity in the system after reactor shutdown. In this case, it may be necessary to chemically remove some of the impurity by a purification process to prevent a build up of long-lived induced activity in the system from restricting access to the plant, and to keep the radiation dose at the working places within the permissible limits. A mathematical modelling is developed. A system of coupled first-order linear differential equations describing adequately the activity behaviour has to be derived and solved. It treats the determination of equilibrium concentrations of impurities on system surface , and the effect of release of fission products from the reactor core

  19. Pre-surgery localization of non-palpable lesions of the breast using a 1.0 Tesla MRI system and a body coil

    International Nuclear Information System (INIS)

    The purpose of the study was to verify whether examination with a non-dedicated MRI body coil, i.e. without complementing electronic hardware, will reliably locate the lesion revealed by the MR-mammography. The idea was that if the results obtained were equal in value, a less expensive alternative for tumor localization might have been found. Material and methods: In 18 patients we performed a contrast enhanced (i.v. 0.2 mmol Gd-DTPA/kg b.w.) breast MRI on a 1.0 Tesla system (Magnetom Impact, Siemens, Erlangen, Germany) using a body coil and a GRE 3D sequence. In prone position, the patients were placed in a customized positioning device offering lateral access to the breast. The localizations were done with a MRI-compatible wire (n=21). In addition, all patients underwent the same imaging protocol using a dedicated breast coil (without localization). For both MRI modalities, the signal intensities of the lesion, the normal breast tissue, and the background noise were measured. The lesion-to-fat contrast (LFC), the lesion-to-breast tissue contrast (LCB) and the percentage of signal change pre- and post-contrast administration were calculated and compared. The localization results were correlated to pathologic findings. Results: There was no difference in lesion detection. Regarding the LCF and LBC, the body coil was superior to the dedicated breast coil. However, the background noise was higher using the body coil. In all cases the localization was successful. (orig./CB)

  20. Philips 3T Intera Magnetic Resonance Imaging System and Upgrade of existing MRI equipment

    Energy Technology Data Exchange (ETDEWEB)

    Evanochko, William T

    2004-05-14

    The objective of this proposal was twofold. First, upgrade existing MRI equipment, specifically a research 4.1T whole-body system. Second, purchase a clinical, state-of-the-art 3T MRI system tailored specifically to cardiovascular and neurological applications. This project was within the guidelines of ''Medical Applications and Measurement Science''. The goals were: [1] to develop beneficial applications of magnetic resonance imaging; [2] discover new applications of MR strategies for medical research; and [2] apply them for clinical diagnosis. Much of this proposal searched for breakthroughs in this noninvasive and nondestructive imaging technology. Finally, this proposal's activities focused on research in the basic science of chemistry, biochemistry, physics, and engineering as applied to bioengineering. The centerpiece of this grant was our 4.1T ultra-high field whole-body nuclear magnetic resonance system and the newly acquired state-of-the-art, heart and head dedicated 3T clinical MRI system. We have successfully upgraded the equipment for the 4.1T system so that it is now state-of-the-art with new gradient and radio frequency amplifiers. We also purchase a unique In Vivo EKG monitoring unit that will permit tracking clinical quality EKG signals while the patient is in a high field MR scanner. Important upgrades of a peripheral vascular coil and a state-of-the-art clinical workstation for processing complex heart images were implemented. The most recent acquisition was the purchase of a state-of-the-art Philips 3T Intera clinical MRI system. This system is unique in that the magnet is only 5 1/2 feet long compare to over 12 feet long magnet of our 4.1T MRI system. The 3T MRI system is fully functional and its use and applications are already greatly benefiting the UAB with 200-300 micron resolution brain images and diagnostic quality MR angiography of coronary arteries in less than 5 minutes.

  1. CT and MRI findings of cerebral ischemic lesions in the cortical and perforating arterial system

    Energy Technology Data Exchange (ETDEWEB)

    Kameyama, Masakuni; Udaka, Fukashi; Nishinaka, Kazuto; Kodama, Mitsuo; Urushidani, Makoto; Kawamura, Kazuyuki; Inoue, Haruhisa; Kageyama, Taku [Sumitomo Hospital, Osaka (Japan)

    1995-07-01

    It is clinically useful to divide the location of infarction into the cortical and perforating arterial system. Computerized tomography (CT) and magnetic resonance imaging (MRI) now make the point of infarction a simple and useful task in daily practice. The diagnostic modality has also demonstrated that risk factors and clinical manifestations are different for infarction in the cortical as opposed to the perforating system. In this paper, we present various aspects of images of cerebral ischemia according to CT and/or MRI findings. With the advance of imaging mechanics, diagnostic capability of CT or/and MRI for cerebral infarction has markedly been improved. We must consider these points on evaluating the previously reported results. In addition, we always consider the pathological background of these image-findings for the precise interpretation of their clinical significance. In some instances, dynamic study such as PET or SPECT is needed for real interpretations of CT and/or MRI images. We paid special reference to lacunar stroke and striatocapsular infarct. In addition, `branch atheromatous disease (Caplan)` was considered, in particular, for their specific clinical significances. Large striatocapsular infarcts frequently show cortical signs and symptoms such as aphasia or agnosia in spite of their subcortical localization. These facts, although have previously been known, should be re-considered for their pathoanatomical mechanism. (author).

  2. volBrain: An Online MRI Brain Volumetry System.

    Science.gov (United States)

    Manjón, José V; Coupé, Pierrick

    2016-01-01

    The amount of medical image data produced in clinical and research settings is rapidly growing resulting in vast amount of data to analyze. Automatic and reliable quantitative analysis tools, including segmentation, allow to analyze brain development and to understand specific patterns of many neurological diseases. This field has recently experienced many advances with successful techniques based on non-linear warping and label fusion. In this work we present a novel and fully automatic pipeline for volumetric brain analysis based on multi-atlas label fusion technology that is able to provide accurate volumetric information at different levels of detail in a short time. This method is available through the volBrain online web interface (http://volbrain.upv.es), which is publically and freely accessible to the scientific community. Our new framework has been compared with current state-of-the-art methods showing very competitive results. PMID:27512372

  3. volBrain: An Online MRI Brain Volumetry System

    Science.gov (United States)

    Manjón, José V.; Coupé, Pierrick

    2016-01-01

    The amount of medical image data produced in clinical and research settings is rapidly growing resulting in vast amount of data to analyze. Automatic and reliable quantitative analysis tools, including segmentation, allow to analyze brain development and to understand specific patterns of many neurological diseases. This field has recently experienced many advances with successful techniques based on non-linear warping and label fusion. In this work we present a novel and fully automatic pipeline for volumetric brain analysis based on multi-atlas label fusion technology that is able to provide accurate volumetric information at different levels of detail in a short time. This method is available through the volBrain online web interface (http://volbrain.upv.es), which is publically and freely accessible to the scientific community. Our new framework has been compared with current state-of-the-art methods showing very competitive results.

  4. volBrain: an online MRI brain volumetry system

    Directory of Open Access Journals (Sweden)

    Jose V. Manjon

    2016-07-01

    Full Text Available The amount of medical image data produced in clinical and research settings is rapidly growing resulting in vast amount of data to analyze. Automatic and reliable quantitative analysis tools, including segmentation, allow to analyze brain development and to understand specific patterns of many neurological diseases. This field has recently experienced many advances with successful techniques based on non-linear warping and label fusion. In this work we present a novel and fully automatic pipeline for volumetric brain analysis based on multi-atlas label fusion technology that is able to provide accurate volumetric information at different levels of detail in a short time. This method is available through the volBrain online web interface (http://volbrain.upv.es, which is publically and freely accessible to the scientific community. Our new framework has been compared with current state-of-the-art methods showing very competitive results.

  5. Visual MRI grading system to evaluate atrophy of the supeaspinatus muscle

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyun Kyoung; Hong, Sung Hwan; Yoo, Hye Jin; Choi, Ja Young; Kim, Sae Hoon; Choi, Jung Ah; Kang, Heung Sik [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2014-08-15

    To investigate the interobserver reproducibility and diagnostic feasibility of a visual grading system for assessing atrophy of the supraspinatus muscle on magnetic resonance imaging (MRI). Three independent radiologists retrospectively evaluated the occupying ratio of the supraspinatus muscle in the supraspinatus fossa on 192 shoulder MRI examinations in 188 patients using a 3-point visual grading system (1, ≥ 60%; 2, 30-59%; 3, < 30%) on oblique sagittal T1-weighted images. The inter-reader agreement and the agreement with the reference standard (3-point grades according to absolute occupying ratio values quantitatively measured by directly contouring the muscles on MRI) were analyzed using weighted kappa. The visual grading was applied by a single reader to a group of 100 consecutive patients who had undergone rotator cuff repair to retrospectively determine the association between the visual grades at preoperative state and postsurgical occurrences of retear. The inter-reader weighted kappa value for the visual grading was 0.74 when averaged across three reader pairs (0.70-0.77 for individual reader pairs). The weighted kappa value between the visual grading and the reference standard ranged from 0.75 to 0.83. There was a significant difference in retear rates of the rotator cuff between the 3 visual grades of supraspinatus muscle atrophy on MRI in univariable analysis (p < 0.001), but not in multivariable analysis (p = 0.026). The 3-point visual grading system may be a feasible method to assess the severity of supraspinatus muscle atrophy on MRI and assist in the clinical management of patients with rotator cuff tear.

  6. The ARAC client system: network-based access to ARAC

    International Nuclear Information System (INIS)

    The ARAC Client System allows users (such as emergency managers and first responders) with commonly available desktop and laptop computers to utilize the central ARAC system over the Internet or any other communications link using Internet protocols. Providing cost-effective fast access to the central ARAC system greatly expands the availability of the ARAC capability. The ARAC Client system consists of (1) local client applications running on the remote user's computer, and (2) ''site servers'' that provide secure access to selected central ARAC system capabilities and run on a scalable number of dedicated workstations residing at the central facility. The remote client applications allow users to describe a real or potential them-bio event, electronically sends this information to the central ARAC system which performs model calculations, and quickly receive and visualize the resulting graphical products. The site servers will support simultaneous access to ARAC capabilities by multiple users. The ARAC Client system is based on object-oriented client/server and distributed computing technologies using CORBA and Java, and consists of a large number of interacting components

  7. Design, Development, and Evaluation of a Master-Slave Surgical System for Breast Biopsy under Continuous MRI.

    Science.gov (United States)

    Yang, Bo; Roys, Steven; Tan, U-Xuan; Philip, Mathew; Richard, Howard; Gullapalli, Rao; Desai, Jaydev P

    2014-04-01

    Magnetic Resonance Imaging (MRI) provides superior soft-tissue contrast in cancer diagnosis compared to other imaging modalities. However, the strong magnetic field inside the MRI bore along with limited scanner bore size poses significant challenges. Since current approaches in breast biopsy using MR images is primarily a blind targeting approach, it is necessary to develop a MRI-compatible robot that can avoid multiple needle insertions into the breast tissue. This MRI-compatible robotic system could potentially lead to improvement in the targeting accuracy and reduce sampling errors. A master-slave surgical system has been developed comprising of a MRI-compatible slave robot which consists of one piezo motor and five pneumatic cylinders connected by long pneumatic transmission lines. The slave robot follows the configuration of the master robot, which provides an intuitive manipulation interface for the physician and operates inside the MRI bore to adjust the needle position and orientation and perform needle insertion task. Based on the MRI experiments using the slave robot, there was no significant distortion in the images and hence the slave robot can be safely operated inside the MRI with minimal loss in signal-to-noise ratio (SNR). Ex vivo and in vivo experiments have been conducted to evaluate the performance of the master-slave surgical system.

  8. Final Report: A CdZnTe detector for MRI-compatible SPECT Systems

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Ling-Jian

    2012-12-27

    The key objective of this project is to develop the enabling technology for future MRI-compatible nuclear (e.g. SPECT) imaging system, and to demonstrate the feasibility of performing simultaneous MR and SPECT imaging studies of the same object. During the past three years, we have developed (a) a MRI-compatible ultrahigh resolution gamma ray detector and associated readout electronics, (b) a theoretical approach for modeling the effect of strong magnetic field on SPECT image quality, and (c) a maximum-likelihood (ML) based reconstruction routine with correction for the MR-induced distortion. With this support, we have also constructed a four-head MR-compatible SPECT system and tested the system inside a 3-T clinical MR-scanner located on UI campus. The experimental results obtained with this system have clearly demonstrated that sub-500um spatial resolution can be achieved with a SPECT system operated inside a 3-T MRI scanner. During the past three years, we have accomplished most of the major objectives outlined in the original proposal. These research efforts have laid out a solid foundation the development of future MR-compatible SPECT systems for both pre-clinical and clinical imaging applications.

  9. NASA access mechanism: Graphical user interface information retrieval system

    Science.gov (United States)

    Hunter, Judy; Generous, Curtis; Duncan, Denise

    1993-01-01

    Access to online information sources of aerospace, scientific, and engineering data, a mission focus for NASA's Scientific and Technical Information Program, has always been limited to factors such as telecommunications, query language syntax, lack of standardization in the information, and the lack of adequate tools to assist in searching. Today, the NASA STI Program's NASA Access Mechanism (NAM) prototype offers a solution to these problems by providing the user with a set of tools that provide a graphical interface to remote, heterogeneous, and distributed information in a manner adaptable to both casual and expert users. Additionally, the NAM provides access to many Internet-based services such as Electronic Mail, the Wide Area Information Servers system, Peer Locating tools, and electronic bulletin boards.

  10. NASA Access Mechanism - Graphical user interface information retrieval system

    Science.gov (United States)

    Hunter, Judy F.; Generous, Curtis; Duncan, Denise

    1993-01-01

    Access to online information sources of aerospace, scientific, and engineering data, a mission focus for NASA's Scientific and Technical Information Program, has always been limited by factors such as telecommunications, query language syntax, lack of standardization in the information, and the lack of adequate tools to assist in searching. Today, the NASA STI Program's NASA Access Mechanism (NAM) prototype offers a solution to these problems by providing the user with a set of tools that provide a graphical interface to remote, heterogeneous, and distributed information in a manner adaptable to both casual and expert users. Additionally, the NAM provides access to many Internet-based services such as Electronic Mail, the Wide Area Information Servers system, Peer Locating tools, and electronic bulletin boards.

  11. MRI-guided prostate focal laser ablation therapy using a mechatronic needle guidance system

    Science.gov (United States)

    Cepek, Jeremy; Lindner, Uri; Ghai, Sangeet; Davidson, Sean R. H.; Trachtenberg, John; Fenster, Aaron

    2014-03-01

    Focal therapy of localized prostate cancer is receiving increased attention due to its potential for providing effective cancer control in select patients with minimal treatment-related side effects. Magnetic resonance imaging (MRI)-guided focal laser ablation (FLA) therapy is an attractive modality for such an approach. In FLA therapy, accurate placement of laser fibers is critical to ensuring that the full target volume is ablated. In practice, error in needle placement is invariably present due to pre- to intra-procedure image registration error, needle deflection, prostate motion, and variability in interventionalist skill. In addition, some of these sources of error are difficult to control, since the available workspace and patient positions are restricted within a clinical MRI bore. In an attempt to take full advantage of the utility of intraprocedure MRI, while minimizing error in needle placement, we developed an MRI-compatible mechatronic system for guiding needles to the prostate for FLA therapy. The system has been used to place interstitial catheters for MRI-guided FLA therapy in eight subjects in an ongoing Phase I/II clinical trial. Data from these cases has provided quantification of the level of uncertainty in needle placement error. To relate needle placement error to clinical outcome, we developed a model for predicting the probability of achieving complete focal target ablation for a family of parameterized treatment plans. Results from this work have enabled the specification of evidence-based selection criteria for the maximum target size that can be confidently ablated using this technique, and quantify the benefit that may be gained with improvements in needle placement accuracy.

  12. A United Access Control Model for Systems in Collaborative Commerce

    Directory of Open Access Journals (Sweden)

    Ruo-Fei Han

    2009-06-01

    Full Text Available The latest researches on access control model are dramatically different from conventional ones. Nowadays, most attention is paid to accessing across organizational boundaries. So, how to identify the applicant and determine authorization with limited information; how to express and exchange control rules expediently; how to protect confidential information and enhance collaboration simultaneously, are the most concerned problems. However, for large commercial organizations, a fine management of internal functions is of the same importance as external service management. It is very troublesome to control authorizations merely with attributes and composition of policies introduced from attribute-based access control (ABAC. So, we introduce a united access control model for systems in collaborative commerce, combining the advantages of conventional role-based access control (RBAC, task-based authentication control (TBAC and that of recent ABAC and automated trust negotiation (ATN. Innovational ideas in the model are analyzed, and the implement architecture is discussed. The paper concludes with a summary of the united model’s benefits and future work.

  13. Magnetic resonance-guided upper abdominal biopsies in a high-field wide-bore 3-T MRI system: feasibility, handling, and needle artefacts

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, Jens-Peter; Langner, Soenke; Hegenscheid, Katrin; Hosten, Norbert; Puls, Ralf [Ernst Moritz Arndt University of Greifswald, Department of Radiology, Greifswald (Germany); Evert, Matthias [Ernst Moritz Arndt University of Greifswald, Department of Pathology, Greifswald (Germany); Kickhefel, Antje [Siemens Healthcare, Erlangen (Germany)

    2010-10-15

    To investigate the feasibility and handling of abdominal MRI-guided biopsies in a 3-T MRI system. Over a 1-year period, 50 biopsies were obtained in 47 patients with tumours of the upper abdominal organs guided by 3-T MRI with a large-bore diameter of 70 cm. Lesions in liver (47), spleen (1) and kidney (2) were biopsied with a coaxial technique using a 16-G biopsy needle guided by a T1-weighted three-dimensional gradient recalled echo volumetric interpolated breath-hold examination (T1w-3D-GRE-VIBE) sequence. Sensitivity, specificity, accuracy, complication rate, interventional complexity, room/intervention time and needle artefacts were determined. A sensitivity of 0.93, specificity of 1.0 and accuracy of 0.94 were observed. Three patients required a rebiopsy. There was a minor complications rate of 13.6%, and no major complications were observed. Histopathology revealed 38 malignant lesions, and 3-month follow-up confirmed 9 benign lesions. Mean lesion diameter was 3.4 {+-} 3.1 cm (50% being smaller than 2 cm). Mean needle tract length was 10.8 {+-} 3.3 cm. Median room time was 42.0 {+-} 19.8 min and intervention time 9.3 {+-} 8.1 min. Needle artefact size was about 9-fold greater for perpendicular access versus access parallel to the main magnetic field. Biopsies of the upper abdomen can be performed with great technical success and easy handling because of the large-bore diameter. The MRI-guided biopsy needle had an acceptable susceptibility artefact at 3 T. However future research must aim to reduce the susceptibility effects of the biopsy systems. (orig.)

  14. Central nervous system lesions in adult T-cell leukaemia: MRI and pathology

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, M.; Korogi, Y.; Shigematsu, Y.; Liang, L.; Takahashi, M. [Department of Radiology, Kumamoto University School of Medicine, Honjo, Kumamoto (Japan); Matsuoka, M. [Second Division of Internal Medicine, Kumamoto University School of Medicine, Honjo, Kumamoto (Japan); Yamamoto, T. [Department of Pathology, Kumamoto University School of Medicine, Honjo, Kumamoto (Japan); Jhono, M. [Department of Dermatology, Kumamoto University School of Medicine, Honjo, Kumamoto (Japan); Eto, K. [The National Institute for Minamata Disease, Minamata (Japan)

    2002-07-01

    Adult T-cell leukaemia (ATL) is a T-cell lymphoid neoplasm caused by human T-cell leukaemia virus type I (HTLV-I). Radiological findings in central nervous system (CNS) involvement have not been well characterised. We reviewed the MRI of 18 patients with ATL who developed new neurological symptoms or signs, and pathology specimens from a 53-year-old woman who died of ATL. MRI findings were divided into three categories: definite, probable, and other abnormal. Definite and probable findings were defined as ATL-related. The characteristic findings were multiple parenchymal masses with or without contrast enhancement adjacent to cerebrospinal fluid (CSF) spaced and the deep grey matter of both cerebral hemispheres, plus leptomeningeal lesion. One patient had both cerebral and spinal cord lesions. Other abnormal findings in eight patients included one case of leukoencephalopathy caused by methotrexate. The histology findings consisted of clusters of tumour cells along perivascular spaces, and scattered infiltration of the parenchyma, with nests of tumour cells. Leptomeningeal infiltration by tumour spread into the parenchyma and secondary degeneration of the neuronal tracts was observed. MRI was useful for detecting CNS invasion by ATL and differentiating it from other abnormalities. The MRI findings seemed to correlate well with the histological changes. (orig.)

  15. MINIPILOT SOLAR SYSTEM: DESIGN/OPERATION OF SYSTEM AND RESULTS OF NON-SOLAR TESTING AT MRI

    Science.gov (United States)

    Prior to this project, MRI had carried out work for the Environmental Protection Agency (EPA) on the conceptual design of a solar system for solid waste disposal and a follow-on project to study the feasibility of bench-scale testing of desorption of organics from soil with destr...

  16. Multi-Channel SQUID System for MEG and Ultra-Low-Field MRI

    OpenAIRE

    Zotev, Vadim S.; Matlachov, Andrei N.; Volegov, Petr L.; Sandin, Henrik J.; Espy, Michelle A.; Mosher, John C.; Urbaitis, Algis V.; Newman, Shaun G.; Kraus Jr, Robert H.

    2006-01-01

    A seven-channel system capable of performing both magnetoencephalography (MEG) and ultra-low-field magnetic resonance imaging (ULF MRI) is described. The system consists of seven second-order SQUID gradiometers with 37 mm diameter and 60 mm baseline, having magnetic field resolution of 1.2-2.8 fT/rtHz. It also includes four sets of coils for 2-D Fourier imaging with pre-polarization. The system's MEG performance was demonstrated by measurements of auditory evoked response. The system was also...

  17. Assessment of three different software systems in the evaluation of dynamic MRI of the breast

    Energy Technology Data Exchange (ETDEWEB)

    Kurz, K.D. [Department of Radiology, Stavanger University Hospital, Postbox 8100, Stavanger (Norway)], E-mail: kurk@sus.no; Steinhaus, D. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: Daniele.Steinhaus@med.uni-duesseldorf.de; Klar, V. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: verena.klar@uni-duesseldorf.de; Cohnen, M. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: cohnen@med.uni-duesseldorf.de; Wittsack, H.J. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: wittsack@uni-duesseldorf.de; Saleh, A. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: saleh@uni-duesseldorf.de; Moedder, U. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: moedder@med.uni-duesseldorf.de; Blondin, D. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: blondin@med.uni-duesseldorf.de

    2009-02-15

    Objective: The aim was to compare the diagnostic performance and handling of dynamic contrast-enhanced MRI of the breast with two commercial software solutions ('CADstream' and '3TP') and one self-developed software system ('Mammatool'). Materials and methods: Identical data sets of dynamic breast MRI from 21 patients were evaluated retrospectively with all three software systems. The exams were classified according to the BI-RADS classification. The number of lesions in the parametric mapping was compared to histology or follow-up of more than 2 years. In addition, 25 quality criteria were judged by 3 independent investigators with a score from 0 to 5. Statistical analysis was performed to document the quality ranking of the different software systems. Results: There were 9 invasive carcinomas, one pure DCIS, one papilloma, one radial scar, three histologically proven changes due to mastopathy, one adenosis and two fibroadenomas. Additionally two patients with enhancing parenchyma followed with MRI for more than 3 years and one scar after breast conserving therapy were included. All malignant lesions were classified as BI-RADS 4 or 5 using all software systems and showed significant enhancement in the parametric mapping. 'CADstream' showed the best score on subjective quality criteria. '3TP' showed the lowest number of false-positive results. 'Mammatool' produced the lowest number of benign tissues indicated with parametric overlay. Conclusion: All three software programs tested were adequate for sensitive and efficient assessment of dynamic MRI of the breast. Improvements in specificity may be achievable.

  18. Central nervous system involvement in incontinentia pigmenti: cranial MRI of two siblings

    Energy Technology Data Exchange (ETDEWEB)

    Aydingoez, Ue.; Midia, M. [Department of Radiology, Hacettepe University School of Medicine, Ankara (Turkey)

    1998-06-01

    Incontinentia pigmenti is an uncommon neurocutaneous syndrome characterised by skin lesions, dental and ocular abnormalities and central nervous system involvement. We report the cranial MRI findings in two sisters with this condition. These include hypoplasia of the corpus callosum, enlargement of the lateral ventricles and periventricular white-matter lesions. One girl also had unilateral microphthalmia and rostral agenesis of the corpus callosum, a feature not previously described. (orig.) With 2 figs., 9 refs.

  19. Evaluasi Pemanfaatan Wireless Internet Protocol Access System di Kota Malang

    Directory of Open Access Journals (Sweden)

    Ahmad Budi Setiawan

    2012-03-01

    Full Text Available WIPAS (Wireless Internet Protocol Accsess System adalah salah satu teknologi pita lebar (broadband yang terbaru. Teknologi tersebut dikembangkan berdasarkan model point-to-multipoint access system pada jaringan nirkabel tetap atau Fixed Wireless Access (FWA dengan memanfaatkan pita frekuensi 26-GHz. Dengan besarnya pita frekuensi yang digunakan, teknologi WIPAS dapat menampung kapasitas akses untuk lalu lintas jaringan yang sangat besar. Dalam penelitian ini akan dikaji dan dievaluasi efektifitas penggunaan teknologi WIPAS melalui kasus pemanfaatan teknologi WIPAS untuk pemberdayaan komunitas di kota Malang. Dalam penelitian ini juga akan dideskripsikan pemanfaatan teknologi WIPAS untuk melihat manfaat penggunaan teknologi tersebut. Penelitian ini dilakukan dengan metode kualitatif dengan melakukan evaluasi terhadap infrastruktur yang telah dibangun untuk melihat efektifitas pemanfaatan WIPAS. Hasil penelitian ini adalah sebuah kajian evaluatif tentang pemanfaatan WIPAS di kota Malang dan rekomendasi untuk implementasi lebih lanjut.

  20. Type-Based Access Control in Data-Centric Systems

    Science.gov (United States)

    Caires, Luís; Pérez, Jorge A.; Seco, João Costa; Vieira, Hugo Torres; Ferrão, Lúcio

    Data-centric multi-user systems, such as web applications, require flexible yet fine-grained data security mechanisms. Such mechanisms are usually enforced by a specially crafted security layer, which adds extra complexity and often leads to error prone coding, easily causing severe security breaches. In this paper, we introduce a programming language approach for enforcing access control policies to data in data-centric programs by static typing. Our development is based on the general concept of refinement type, but extended so as to address realistic and challenging scenarios of permission-based data security, in which policies dynamically depend on the database state, and flexible combinations of column- and row-level protection of data are necessary. We state and prove soundness and safety of our type system, stating that well-typed programs never break the declared data access control policies.

  1. Intra-coil interactions in split gradient coils in a hybrid MRI-LINAC system

    Science.gov (United States)

    Tang, Fangfang; Freschi, Fabio; Sanchez Lopez, Hector; Repetto, Maurizio; Liu, Feng; Crozier, Stuart

    2016-04-01

    An MRI-LINAC system combines a magnetic resonance imaging (MRI) system with a medical linear accelerator (LINAC) to provide image-guided radiotherapy for targeting tumors in real-time. In an MRI-LINAC system, a set of split gradient coils is employed to produce orthogonal gradient fields for spatial signal encoding. Owing to this unconventional gradient configuration, eddy currents induced by switching gradient coils on and off may be of particular concern. It is expected that strong intra-coil interactions in the set will be present due to the constrained return paths, leading to potential degradation of the gradient field linearity and image distortion. In this study, a series of gradient coils with different track widths have been designed and analyzed to investigate the electromagnetic interactions between coils in a split gradient set. A driving current, with frequencies from 100 Hz to 10 kHz, was applied to study the inductive coupling effects with respect to conductor geometry and operating frequency. It was found that the eddy currents induced in the un-energized coils (hereby-referred to as passive coils) positively correlated with track width and frequency. The magnetic field induced by the eddy currents in the passive coils with wide tracks was several times larger than that induced by eddy currents in the cold shield of cryostat. The power loss in the passive coils increased with the track width. Therefore, intra-coil interactions should be included in the coil design and analysis process.

  2. Volumetric MRI of the limbic system: anatomic determinants

    Energy Technology Data Exchange (ETDEWEB)

    Bilir, E.; Craven, W.; Hugg, J.; Gilliam, F.; Martin, R.; Faught, E.; Kuzniecky, R. [UAB Epilepsy Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL (United States)

    1998-03-01

    The limbic system comprises the hippocampal formation, fornix, mamillary bodies, thalamus, and other integrated structures. It is involved in complex functions including memory and emotion and in diseases such as temporal lobe epilepsy. Volume measurements of the amygdala and hippocampus have been used reliably to study patients with temporal lobe epilepsy but have not extended to other limbic structures. We performed volume measurements of hippocampus, amygdala, fornix and mamillary bodies in healthy individuals. Measurements of the amygdala, hippocampus, fornix and mamillary bodies revealed significant differences in volume between right and left sides (P < 0.001). The intraclass coefficient of variation for measurements was high for all structures except the mamillary bodies. Qualitative image assessment of the same structures revealed no asymmetries between the hemispheres. This technique can be applied to the study of disorders affecting the limbic system. (orig.) With 4 figs., 2 tabs., 23 refs.

  3. Functional MRI of the olfactory system in conscious dogs.

    Directory of Open Access Journals (Sweden)

    Hao Jia

    Full Text Available We depend upon the olfactory abilities of dogs for critical tasks such as detecting bombs, landmines, other hazardous chemicals and illicit substances. Hence, a mechanistic understanding of the olfactory system in dogs is of great scientific interest. Previous studies explored this aspect at the cellular and behavior levels; however, the cognitive-level neural substrates linking them have never been explored. This is critical given the fact that behavior is driven by filtered sensory representations in higher order cognitive areas rather than the raw odor maps of the olfactory bulb. Since sedated dogs cannot sniff, we investigated this using functional magnetic resonance imaging of conscious dogs. We addressed the technical challenges of head motion using a two pronged strategy of behavioral training to keep dogs' head as still as possible and a single camera optical head motion tracking system to account for residual jerky movements. We built a custom computer-controlled odorant delivery system which was synchronized with image acquisition, allowing the investigation of brain regions activated by odors. The olfactory bulb and piriform lobes were commonly activated in both awake and anesthetized dogs, while the frontal cortex was activated mainly in conscious dogs. Comparison of responses to low and high odor intensity showed differences in either the strength or spatial extent of activation in the olfactory bulb, piriform lobes, cerebellum, and frontal cortex. Our results demonstrate the viability of the proposed method for functional imaging of the olfactory system in conscious dogs. This could potentially open up a new field of research in detector dog technology.

  4. Towards an hybrid system for annotating brain MRI images

    OpenAIRE

    Mechouche, Ammar; Golbreich, Christine; Gibaud, Bernard

    2006-01-01

    This paper describes a method combining symbolic and numerical techniques for annotating brain Magnetic Resonance images. The goal is to assist existing automatic labelling methods which are mostly statistical in nature and do not work very well in certain situations such as the presence of lesions. The system uses existing statistical methods for generating ABox facts that constitute a set of initial information sufficient for fruitful reasoning. The reasoning is supported by an OWL ontology...

  5. A portable marine geophysical data access and management system

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.; Narvekar, P.

    information ? Reasonable execution speed for mana g ing/accessing high volume of data ? A flexible and multi - track querying system ? Facilities to save, open, e dit and resubmit the query ? Plotting the queried data on the map with zoom, pan.... Following are four major software modules: ? Data import module ? Query builder or search module ? Data visualization and download module ? Data management (administrative) module. On execution of the GPDAMS program, the main t i tle screen...

  6. DAISY Producer: An integrated production management system for accessible media

    OpenAIRE

    Egli, Christian

    2011-01-01

    Large scale production of accessible media above and beyond DAISY Talking Books requires management of the workflow from the initial scan to the output of the media production. DAISY Producer was created to help manage this process. It tracks the transformation of hard copy or electronic content to DTBook XML at any stage of the workflow and interfaces to existing order processing systems. Making use of DAISY Pipeline and Liblouis, DAISY Producer fully automates the generation of on-demand, u...

  7. Access control and interlock system at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Forrestal, J.; Hogrefe, R.; Knott, M.; McDowell, W.; Reigle, D.; Solita, L.; Koldenhoven, R.; Haid, D. [Argonne National Lab., IL (United States). Advanced Photon Source

    1997-08-01

    The Advanced Photon Source (APS) consists of a linac, position accumulator ring (PAR), booster synchrotron, storage ring, and up to 70 experimental beamlines. The Access Control and Interlock System (ACIS) utilizes redundant programmable logic controllers (PLCs) and a third hard-wired chain to protect personnel from prompt radiation generated by the linac, PAR, synchrotron, and storage ring. This paper describes the ACIS`s design philosophy, configuration, hardware, functionality, validation requirements, and operational experience.

  8. Task-role-based Access Control Model in Smart Health-care System

    OpenAIRE

    Wang Peng; Jiang Lingyun

    2015-01-01

    As the development of computer science and smart health-care technology, there is a trend for patients to enjoy medical care at home. Taking enormous users in the Smart Health-care System into consideration, access control is an important issue. Traditional access control models, discretionary access control, mandatory access control, and role-based access control, do not properly reflect the characteristics of Smart Health-care System. This paper proposes an advanced access control model for...

  9. RFID Based Security Access Control System with GSM Technology

    Directory of Open Access Journals (Sweden)

    Peter Adole

    2016-08-01

    Full Text Available The security challenges being encountered in many places today require electronic means of controlling access to secured premises in addition to the available security personnel. Various technologies were used in different forms to solve these challenges. The Radio Frequency Identification (RFID Based Access Control Security system with GSM technology presented in this work helps to prevent unauthorized access to controlled environments (secured premises. This is achieved mainly through the use of a Radio Frequency Identification System with operating frequency of 125 KHz, Microcontroller programmed to send control signals, DC motor, relay, buzzer, Liquid Crystal Display (LCD and GSM/GPRS Modem.Once the RFID tag which contains the user’s unique information is scan by the RFID reader and confirmed match with the information stored in the microcontroller, the microcontroller is instructed to turn ON the DC motor through L293D driver, display “USER NUMBER and CARD NUMBER” on the LCD and activates the GSM/GPRS modem to send SMS alert “AUTHORIZED, valid RFID card shown, User is allowed to enter, user number” to security personnel. Else, the DC Motor remained OFF, LCD displays “READ RFID CARD NOT VALID”, buzzer turns ON for about 5seconds and GSM/GPRS modem activated to send “ UNAUTHORIZED, invalid RFID card is used to access the security system” to the security personnel. The electronic circuit was implemented, the codes for microcontroller were written in assembly language, debugged and compiled using the KEIL Micro vision 4 integrated development environment. The resultant Hex files were programmed into the memories of the microcontrollers with the aid of a universal programmer. Hardware simulation was carried out using the Proteus Virtual System Modelling (VSM version 8.0.An importation implication of this paper is that the system is cheaper to maintain and more efficient in comparison with a manually operated type or key lock

  10. RF Head Coil Design with Improved RF Magnetic Near-Fields Uniformity for Magnetic Resonance Imaging (MRI) Systems

    OpenAIRE

    Sohn, Sung-Min; DelaBarre, Lance; Gopinath, Anand; Vaughan, John Thomas

    2014-01-01

    Higher magnetic field strength in magnetic resonance imaging (MRI) systems offers higher signal-to-noise ratio (SNR), contrast, and spatial resolution in MR images. However, the wavelength in ultra-high fields (7 tesla and beyond) becomes shorter than the human body at the Larmor frequency with increasing static magnetic field (B0) of MRI system. At short wavelengths, interference effect appears resulting in non- uniformity of the RF magnetic near-field (B1) over the subject and MR images may...

  11. ACCESS Earth: Promoting Accessibility to Earth System Science for Students with Disabilities

    Science.gov (United States)

    Locke, S. M.; Cohen, L.; Lightbody, N.

    2001-05-01

    ACCESS Earth is an intensive summer institute for high school students with disabilities and their teachers that is designed to encourage students with disabilities to consider careers in earth system science. Participants study earth system science concepts at a Maine coastal estuary, using Geographic Information Systems, remote sensing, and field observations to evaluate the impacts of climate change, sea level rise, and development on coastal systems. Teachers, students, and scientists work together to adapt field and laboratory activities for persons with disabilities, including those with mobility and visual impairments. Other sessions include demonstrations of assistive technology, career discussions, and opportunities for students to meet with successful scientists with disabilities from throughout the U.S. The summer institute is one of several programs in development at the University of Southern Maine to address the problem of underrepresentation of people with disabilities in the earth sciences. Other projects include a mentoring program for high school students, a web-based clearinghouse of resources for teaching earth sciences to students with disabilities, and guidebooks for adaptation of popular published earth system science curricula for disabled learners.

  12. Towards motion insensitive EEG-fMRI: Correcting motion-induced voltages and gradient artefact instability in EEG using an fMRI prospective motion correction (PMC) system.

    Science.gov (United States)

    Maziero, Danilo; Velasco, Tonicarlo R; Hunt, Nigel; Payne, Edwin; Lemieux, Louis; Salmon, Carlos E G; Carmichael, David W

    2016-09-01

    The simultaneous acquisition of electroencephalography and functional magnetic resonance imaging (EEG-fMRI) is a multimodal technique extensively applied for mapping the human brain. However, the quality of EEG data obtained within the MRI environment is strongly affected by subject motion due to the induction of voltages in addition to artefacts caused by the scanning gradients and the heartbeat. This has limited its application in populations such as paediatric patients or to study epileptic seizure onset. Recent work has used a Moiré-phase grating and a MR-compatible camera to prospectively update image acquisition and improve fMRI quality (prospective motion correction: PMC). In this study, we use this technology to retrospectively reduce the spurious voltages induced by motion in the EEG data acquired inside the MRI scanner, with and without fMRI acquisitions. This was achieved by modelling induced voltages from the tracking system motion parameters; position and angles, their first derivative (velocities) and the velocity squared. This model was used to remove the voltages related to the detected motion via a linear regression. Since EEG quality during fMRI relies on a temporally stable gradient artefact (GA) template (calculated from averaging EEG epochs matched to scan volume or slice acquisition), this was evaluated in sessions both with and without motion contamination, and with and without PMC. We demonstrate that our approach is capable of significantly reducing motion-related artefact with a magnitude of up to 10mm of translation, 6° of rotation and velocities of 50mm/s, while preserving physiological information. We also demonstrate that the EEG-GA variance is not increased by the gradient direction changes associated with PMC. Provided a scan slice-based GA template is used (rather than a scan volume GA template) we demonstrate that EEG variance during motion can be supressed towards levels found when subjects are still. In summary, we show that

  13. MRI in central nervous system infections: A simplified patterned approach

    Institute of Scientific and Technical Information of China (English)

    Krithika; Rangarajan; Chandan; J; Das; Atin; Kumar; Arun; Kumar; Gupta

    2014-01-01

    Recognition and characterization of central nervous system infections poses a formidable challenge to the neuro-radiologist.Imaging plays a vital role,the lesions typically being relatively inaccessible to tisue sampling.The results of an accurate diagnosis are endlessly re-warding,given the availability of excellent pharmaco-logical regimen.The availability of numerous magnetic resonance(MR)sequences which provide functional and molecular information is a powerful tool in the hands of the radiologist.However,the plethora of se-quences and the possibilities on each sequence is also intimidating,and often confusing as well as time con-suming.While a large number of reviews have already described in detail the possible imaging findings in each infection,we intend to classify infections based on their imaging characteristics.In this review we describe an algorithm for first classifying the imaging findings into patterns based on basic MR sequences(T1,T2 and enhancement pattern with Gadolinium),and then sub-classify them based on more advanced molecular and functional sequences(Diffusion,Perfusion,Susceptibili-ty imaging,MR Spectroscopy).This patterned approachis intended as a guide to radiologists in-training and in-practice for quickly narrowing their list of differentials when faced with a clinical challenge.The entire content of the article has also been summarised in the form of flow-charts for the purpose of quick reference.

  14. Privacy and Access Control for IHE-Based Systems

    Science.gov (United States)

    Katt, Basel; Breu, Ruth; Hafner, Micahel; Schabetsberger, Thomas; Mair, Richard; Wozak, Florian

    Electronic Health Record (EHR) is the heart element of any e-health system, which aims at improving the quality and efficiency of healthcare through the use of information and communication technologies. The sensitivity of the data contained in the health record poses a great challenge to security. In this paper we propose a security architecture for EHR systems that are conform with IHE profiles. In this architecture we are tackling the problems of access control and privacy. Furthermore, a prototypical implementation of the proposed model is presented.

  15. Authorisation and access control for electronic health record systems.

    Science.gov (United States)

    Blobel, Bernd

    2004-03-31

    Enabling the shared care paradigm, centralised or even decentralised electronic health record (EHR) systems increasingly become core applications in hospital information systems and health networks. For realising multipurpose use and reuse as well as inter-operability at knowledge level, EHR have to meet special architectural requirements. The component-oriented and model-based architecture should meet international standards. Especially in extended health networks realising inter-organisational communication and co-operation, authorisation cannot be organised at user level anymore. Therefore, models, methods and tools must be established to allow formal and structured policy definition, policy agreements, role definition, authorisation and access control. Based on the author's international engagement in EHR architecture and security standards referring to the revision of CEN ENV 13606, the GEHR/open EHR approach, HL7 and CORBA, models for health-specific and EHR-related roles, for authorisation management and access control have been developed. The basic concept is the separation of structural roles defining organisational entity-to-entity relationships and enabling specific acts on the one hand, and functional roles bound to specific activities and realising rights and duties on the other hand. Aggregation of organisational, functional, informational and technological components follows specific rules. Using UML and XML, the principles as well as some examples for analysis, design, implementation and maintenance of policy and authorisation management as well as access control have been practically implemented.

  16. Authorisation and access control for electronic health record systems.

    Science.gov (United States)

    Blobel, Bernd

    2004-03-31

    Enabling the shared care paradigm, centralised or even decentralised electronic health record (EHR) systems increasingly become core applications in hospital information systems and health networks. For realising multipurpose use and reuse as well as inter-operability at knowledge level, EHR have to meet special architectural requirements. The component-oriented and model-based architecture should meet international standards. Especially in extended health networks realising inter-organisational communication and co-operation, authorisation cannot be organised at user level anymore. Therefore, models, methods and tools must be established to allow formal and structured policy definition, policy agreements, role definition, authorisation and access control. Based on the author's international engagement in EHR architecture and security standards referring to the revision of CEN ENV 13606, the GEHR/open EHR approach, HL7 and CORBA, models for health-specific and EHR-related roles, for authorisation management and access control have been developed. The basic concept is the separation of structural roles defining organisational entity-to-entity relationships and enabling specific acts on the one hand, and functional roles bound to specific activities and realising rights and duties on the other hand. Aggregation of organisational, functional, informational and technological components follows specific rules. Using UML and XML, the principles as well as some examples for analysis, design, implementation and maintenance of policy and authorisation management as well as access control have been practically implemented. PMID:15066555

  17. Licensed Shared Access System Possibilities for Public Safety

    Directory of Open Access Journals (Sweden)

    Kalle Lähetkangas

    2016-01-01

    Full Text Available We investigate the licensed shared access (LSA concept based spectrum sharing ideas between public safety (PS and commercial radio systems. While the concept of LSA has been well developed, it has not been thoroughly investigated from the public safety (PS users’ point of view, who have special requirements and also should benefit from the concept. Herein, we discuss the alternatives for spectrum sharing between PS and commercial systems. In particular, we proceed to develop robust solutions for LSA use cases where connections to the LSA system may fail. We simulate the proposed system with different failure models. The results show that the method offers reliable LSA spectrum sharing in various conditions assuming that the system parameters are set properly. The paper gives guidelines to set these parameters.

  18. A Rewritable, Random-Access DNA-Based Storage System

    Science.gov (United States)

    Tabatabaei Yazdi, S. M. Hossein; Yuan, Yongbo; Ma, Jian; Zhao, Huimin; Milenkovic, Olgica

    2015-09-01

    We describe the first DNA-based storage architecture that enables random access to data blocks and rewriting of information stored at arbitrary locations within the blocks. The newly developed architecture overcomes drawbacks of existing read-only methods that require decoding the whole file in order to read one data fragment. Our system is based on new constrained coding techniques and accompanying DNA editing methods that ensure data reliability, specificity and sensitivity of access, and at the same time provide exceptionally high data storage capacity. As a proof of concept, we encoded parts of the Wikipedia pages of six universities in the USA, and selected and edited parts of the text written in DNA corresponding to three of these schools. The results suggest that DNA is a versatile media suitable for both ultrahigh density archival and rewritable storage applications.

  19. Quality assurance in functional MRI

    DEFF Research Database (Denmark)

    Liu, Thomas T; Glover, Gary H; Mueller, Bryon A;

    2015-01-01

    Over the past 20 years, functional magnetic resonance imaging (fMRI) has ben- efited greatly from improvements in MRI hardware and software. At the same time, fMRI researchers have pushed the technical limits of MRI systems and greatly in- fluenced the development of state-of-the-art systems. Min...

  20. Bluetooth Navigation System Using WI-FI Access Points

    Directory of Open Access Journals (Sweden)

    Rohit Agrawal

    2012-04-01

    Full Text Available There have been various navigation and tracking systems being developed with the help of technologies like GPS, GSM, Bluetooth, IR, Wi-Fi and Radar. Outdoor positioning systems have been deployed quite successfully using GPS but positioning systems for indoor environments still do not have widespread deployment due to various reasons. Most of these use only a single technology for positioning but using more than one in cooperation with each other is always advantageous for obtaining greater accuracy. Particularly, the ones which use Bluetooth are better since they would enhance the scalability of such a system because of the fact that this technology is in use by the common people so it would always be easy to track them. Moreover it would also reduce the hardware installation cost to some extent. The systemthat has been introduced here uses bluetooth primarily for positioning and tracking in combination with Wi-Fi access points. The reason that makes the commercial application of such a system easier and cheaper is that most of the localized areas today like college campus, offices are being provided withinternet connectivity using these access points.

  1. Fetal MRI

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, D.; Brugger, P.C. [University Hospital of Vienna (Austria). Division of Neuroradiology

    2004-07-01

    New, ultrafast sequences have made it possible to obtain MR images of the fetus without maternal sedation or immobilization of the fetus itself. While fetal MRI began as an adjunct to ultrasound, it has now been shown that MRI can provide additional information that may change prognosis, the management of pregnancy, or the treatment of the newborn child. It is of particular value in the assessment of malformations of the central nervous system. The steady development and adaptation of MR-sequences to the needs of fetal imaging has led to new indications that can support prognostic and therapeutic decisions. (orig.)

  2. MRI Artifacts

    Directory of Open Access Journals (Sweden)

    Abed Al Nasser Assi

    2009-12-01

    Full Text Available   "nMagnetic resonance imaging (MRI has become more and more frequently used in medical imaging diagnostic in recent years. Radiologists and technicians working at these systems are relatively often confronted with image artifacts related to the radiowave with strong magnetic in the scanner. Many artifacts may be corrected or modulated through an understanding of their cause. This requires familiarity with scanner design; theory of operation; and image acquisition. The purpose of this review article is to present the most relevant artifacts that arise in MRI scanner, to provide some physical background on the formation of artifacts, and to suggest strategies to reduce or avoid these artifacts. The most frequent artifacts that can occur during MRI scanning are Motion related artifacts; Para-magnetic artifacts; Phase Wrap artifacts; Frequency artifacts; Susceptibility artifacts; Clipping artefact; Chemical Shift artifact and "Zebra" artefact .    "n  

  3. MRI zoo

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    The basic idea was to use MRI to produce a sequence of 3D gray scale image slices of various animals, subsequentlyimaged with a clinical CT system. For this purpose, these animals were used: toad, lungfish, python snake and a horseshoe crab. Each animal was sacrificed according to standard proced...

  4. A recently developed MRI scoring system for hand osteoarthritis: its application in a clinical setting.

    Science.gov (United States)

    Ramonda, Roberta; Favero, Marta; Vio, Stefania; Lacognata, Carmelo; Frallonardo, Paola; Belluzzi, Elisa; Campana, Carla; Lorenzin, Mariagrazia; Ortolan, Augusta; Angelini, Federico; Piccoli, Antonio; Oliviero, Francesca; Punzi, Leonardo

    2016-08-01

    This study aimed to apply the recently proposed Oslo hand osteoarthritis magnetic resonance imaging (MRI) scoring system to evaluate MRI findings in a cohort of patients affected by long-standing erosive hand osteoarthritis (EHOA). Eleven female EHOA patients (median 59 [interquartile range 62-52] years, disease duration 9.5 [interquartile range 13-3.75] years) underwent MRI (1.5 T) of the dominant hand, and synovitis, bone marrow lesions (BMLs), joint space narrowing, osteophytes, cysts, malalignment, and erosions were scored using the Oslo scoring system. Intra- and inter-reader reliability were assessed. The patients also underwent X-ray examination, and bone features were evaluated using the same scoring system. Pain and tenderness were assessed during a physical examination. Spearman's non-parametric test was used to analyze the correlations between variables. MRI intra- and inter-reader reliability were found between good and moderate for many features. No statistical differences were found between the radiographs and MRI with regard to detection of JSN, malalignment, and bone erosions. Synovitis was detected in 39.8 % of the 80 joints examined (in a mild form in 80 %), erosions were found in 51.1 %, and BMLs were identified in 20.5 and 23.9 % at the distal and the proximal side, respectively. BMLs at both the proximal and distal ends were correlated with tender joints (BML distal p = 0.0013, BML proximal p = 0.012). The presence of synovitis was correlated with tenderness (p = 0.004) and erosions at both the distal and proximal joints (p = 0.004). The presence of erosions correlated with tender joints (p < 0.01) and the mean visual analog scale (VAS) score (distal p = 0.03, proximal p = 0.01). Synovitis and BMLs were correlated with clinical symptoms in our patients affected with long-standing EHOA. PMID:27236512

  5. Electron contamination modeling and reduction in a 1 T open bore inline MRI-linac system

    Energy Technology Data Exchange (ETDEWEB)

    Oborn, B. M. [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500, Australia and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Kolling, S. [Sydney Medical School, University of Sydney, NSW 2006 (Australia); Metcalfe, P. E. [Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia); Crozier, S. [School of Information Technology and Electric Engineering, University of Queensland, QLD 4072 (Australia); Litzenberg, D. W. [Department of Radiation Oncology, University of Michigan Hospital and Health Systems, Ann Arbor, Michigan 48109 (United States); Keall, P. J. [Sydney Medical School, University of Sydney, NSW 2006, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia)

    2014-05-15

    Purpose: A potential side effect of inline MRI-linac systems is electron contamination focusing causing a high skin dose. In this work, the authors reexamine this prediction for an open bore 1 T MRI system being constructed for the Australian MRI-Linac Program. The efficiency of an electron contamination deflector (ECD) in purging electron contamination from the linac head is modeled, as well as the impact of a helium gas region between the deflector and phantom surface for lowering the amount of air-generated contamination. Methods: Magnetic modeling of the 1 T MRI was used to generate 3D magnetic field maps both with and without the presence of an ECD located immediately below the MLC’s. Forty-seven different ECD designs were modeled and for each the magnetic field map was imported into Geant4 Monte Carlo simulations including the linac head, ECD, and a 30 × 30 × 30 cm{sup 3} water phantom located at isocenter. For the first generation system, the x-ray source to isocenter distance (SID) will be 160 cm, resulting in an 81.2 cm long air gap from the base of the ECD to the phantom surface. The first 71.2 cm was modeled as air or helium gas, with the latter encased between two windows of 50 μm thick high density polyethlyene. 2D skin doses (at 70 μm depth) were calculated across the phantom surface at 1 × 1 mm{sup 2} resolution for 6 MV beams of field size of 5 × 5, 10 × 10, and 20 × 20 cm{sup 2}. Results: The skin dose was predicted to be of similar magnitude as the generic systems modeled in previous work, 230% to 1400% ofD {sub max} for 5 × 5 to 20 × 20 cm{sup 2}, respectively. Inclusion of the ECD introduced a nonuniformity to the MRI imaging field that ranged from ∼20 to ∼140 ppm while the net force acting on the ECD ranged from ∼151 N to ∼1773 N. Various ECD designs were 100% efficient at purging the electron contamination into the ECD magnet banks; however, a small percentage were scattered back into the beam and continued to the phantom

  6. MR-guided discography using an open 1 Tesla MRI system

    International Nuclear Information System (INIS)

    To evaluate the feasibility of MR-guided discography using an open 1 Tesla MRI system. 48 disc segments of 41 patients scheduled for intradiscal thermal treatment, total disc replacement or spondylodesis were examined. A 1.0-T open MRI was used for instrument guidance and imaging. After primary disc puncture under guidance of interactive PDw TSE imaging, 1-2 ml of gadolinium contrast saline mixture was injected into the disc. The occurrence of memory pain during injection was recorded. Axial and sagittal T1w TSE images with and without fat saturation were obtained. All MRI discograms were analysed by two readers, who were blinded to the clinical findings. Overall, the placement of the puncture needle in the targeted disc was accurate under real-time MR guidance. Injections were technically successful in all cases. No major complications occurred. The mean procedure time was 17 min (range 13-34 min). Image quality of contrast-enhanced MR discograms was excellent when using an optimized gadolinium contrast saline mixture of 1:600. Memory pain was detected in 16 out of 48 affected segments. MR-guided discography is accurate and safe. Multiplanar dynamic imaging facilitates the puncture of discs and provides high-quality MR discograms. (orig.)

  7. EEG-fMRI based information theoretic characterization of the human perceptual decision system.

    Directory of Open Access Journals (Sweden)

    Dirk Ostwald

    Full Text Available The modern metaphor of the brain is that of a dynamic information processing device. In the current study we investigate how a core cognitive network of the human brain, the perceptual decision system, can be characterized regarding its spatiotemporal representation of task-relevant information. We capitalize on a recently developed information theoretic framework for the analysis of simultaneously acquired electroencephalography (EEG and functional magnetic resonance imaging data (fMRI (Ostwald et al. (2010, NeuroImage 49: 498-516. We show how this framework naturally extends from previous validations in the sensory to the cognitive domain and how it enables the economic description of neural spatiotemporal information encoding. Specifically, based on simultaneous EEG-fMRI data features from n = 13 observers performing a visual perceptual decision task, we demonstrate how the information theoretic framework is able to reproduce earlier findings on the neurobiological underpinnings of perceptual decisions from the response signal features' marginal distributions. Furthermore, using the joint EEG-fMRI feature distribution, we provide novel evidence for a highly distributed and dynamic encoding of task-relevant information in the human brain.

  8. ISPMER: Integrated system for combined PET, MRI, and electrophysiological recording in somatosensory studies in rats

    International Nuclear Information System (INIS)

    The present study developed an integrated system for use in combined PET, MRI, and electrophysiological recording in somatosensory studies in rats, called ISPMER. A stereotaxic frame was designed for animal positioning that could be used in all three measurement modalities, and its dimensions complied with the gold standard of the Paxinos and Watson rat brain atlas. A graphical user interface was developed for analyzing the data using several signal processing algorithms. This integrated system provides a novel interface for the recording and processing of three-dimensional neuronal signals in three modalities

  9. Towards Voluntary Interoperable Open Access Licenses for the Global Earth Observation System of Systems (GEOSS)

    NARCIS (Netherlands)

    Onsrud, H.; Campbell, J.; Van Loenen, B.

    2010-01-01

    Access to earth observation data has become critically important for the wellbeing of society. A major impediment to achieving widespread sharing of earth observation data is lack of an operational web-wide system that is transparent and consistent in allowing users to legally access and use the ear

  10. Low-field MRI for studies of human pulmonary physiology and traumatic brain injury

    Science.gov (United States)

    Wilson, Alyssa; Devience, Stephen; Rosen, Matthew; Walsworth, Ronald

    2011-05-01

    We describe recent progress on the development of an open-access low-magnetic-field MRI system for studies of human pulmonary physiology and traumatic brain injury. Low-field MRI benefits from reduced magnetic susceptibility effects and can provide high-resolution images of the human body when used with hyperpolarized media such as 3He and 129Xe.

  11. Extraction of the human cerebral ventricular system from MRI: inclusion of anatomical knowledge and clinical perspective

    Science.gov (United States)

    Aziz, Aamer; Hu, Qingmao; Nowinski, Wieslaw L.

    2004-04-01

    The human cerebral ventricular system is a complex structure that is essential for the well being and changes in which reflect disease. It is clinically imperative that the ventricular system be studied in details. For this reason computer assisted algorithms are essential to be developed. We have developed a novel (patent pending) and robust anatomical knowledge-driven algorithm for automatic extraction of the cerebral ventricular system from MRI. The algorithm is not only unique in its image processing aspect but also incorporates knowledge of neuroanatomy, radiological properties, and variability of the ventricular system. The ventricular system is divided into six 3D regions based on the anatomy and its variability. Within each ventricular region a 2D region of interest (ROI) is defined and is then further subdivided into sub-regions. Various strict conditions that detect and prevent leakage into the extra-ventricular space are specified for each sub-region based on anatomical knowledge. Each ROI is processed to calculate its local statistics, local intensity ranges of cerebrospinal fluid and grey and white matters, set a seed point within the ROI, grow region directionally in 3D, check anti-leakage conditions and correct growing if leakage occurs and connects all unconnected regions grown by relaxing growing conditions. The algorithm was tested qualitatively and quantitatively on normal and pathological MRI cases and worked well. In this paper we discuss in more detail inclusion of anatomical knowledge in the algorithm and usefulness of our approach from clinical perspective.

  12. A modular, computer-controlled system for olfactory stimulation in the MRI environment.

    Science.gov (United States)

    Andrieu, Patrice; Bonnans, Vincent; Meneses, Jaime; Millot, Jean-Louis; Moulin, Thierry; Gharbi, Tijani

    2014-03-01

    Although the cerebral networks involved in sensory perception are of general interest in neuroscience, registration of the effects of olfactory stimulation, especially in a magnetic resonance imaging (MRI) environment, presents particular problems and constraints. This article presents details of a reliable and portable system for olfactory stimulation that is modular in design and based on microcontroller technology. It has the following characteristics: (1) It is under software control; (2) the presentation of olfactory stimulation can be synchronized with respiration; (3) it can be manually controlled; and (4) it is fully compatible with an MRI environment. The principle underlying this system is to direct an odor to the subject's nostrils by switching airflow to different odor diffusers. The characteristics of this system were established using (1) ultraviolet (UV) spectroscopy, to measure its response time, and (2) gas chromatography, to measure the repeatability of odor presentation in terms of gas concentration. A response time of 200 ± 25 ms was obtained for the system, and the standard deviations of the gas concentration delivered during stimulation ranged from 1.5% to 22%, depending on the odor, the airflow, and the dilution of the odor used. Since it is portable, controlled by software, and reliable, on the basis of the results we obtained, this system will lend itself to a wide range of applications in olfactory neuroscience.

  13. Vulcanus 2.0: A Recommender System for Accessibility

    Directory of Open Access Journals (Sweden)

    Ismael Gomes Cardoso

    2016-04-01

    Full Text Available Even though the use of recommender systems is already widely spread in several application areas, there is still a lack of studies for accessibility research field. One of these attempts to use recommender system benefits for accessibility needs is Vulcanus. The Vulcanus recommender system uses similarity analysis to compare user's trails. In this way, it is possible to take advantage of the user's past behavior and distribute personalized content and services. The Vulcanus combined concepts from ubiquitous computing, such as user profiles, context awareness, trails management, and similarity analysis. It uses two different approaches for trails similarity analysis: resources patterns and categories patterns. In this work we performed an asymptotic analysis, identifying Vulcanus' algorithm complexity. Furthermore we also propose improvements achieved by dynamic programming technique, so the ordinary case is improved by using a bottom-up approach. With that approach, many unnecessary comparisons can be skipped and now Vulcanus 2.0 is presented with improvements in its average case scenario.

  14. Permanent Magnet System for MRI with Constant Gradient mechanically adjustable in Direction and Strength

    CERN Document Server

    Blümler, Peter

    2015-01-01

    A design for a permanent magnet system is proposed that generates spatially homogeneous, constant magnetic field gradients, thus creating conditions suitable for MRI without gradient coils and amplifiers. This is achieved by superimposing a weak Halbach quadrupole on a strong Halbach dipole. Rotation of either the quadrupole or the entire magnet assembly can be used to generate 2D images via filtered back-projection. Additionally, the mutual rotation of two quadrupoles can be used to scale the resulting gradient. If both gradients have identical strength the gradient can even be made to vanish. The concept is demonstrated by analytical considerations and FEM-simulations.

  15. Accessibility of a Destination-Based Transportation System: A Large Airport Study

    Institute of Scientific and Technical Information of China (English)

    SHI Jing; YING Xiwen

    2008-01-01

    The accessibility of a destination-based transportation system is defined to quantify the perform-ance of transportation systems which access a distinct destination. The access cost is used to reflect the utility of the transportation system including the fatigue and inconvenience in the total cost. The cost is quan-tified by two coefficients which represent the different characteristics of various people. The average cost and the income-relative accessibility are used to describe various aspects of the accessibility and to evaluate the accessibility of a destination-based system. A case study uses data from the Kunming transpor-tation system to evaluate the accessibility of the present city airport. The calibrated coefficients are then used to evaluate the transportation system to the new Kunming international airport. The results show that this transportation accessibility evaluation can be combined with transportation planning to study transporta-tion sub-systems.

  16. 76 FR 60398 - Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control...

    Science.gov (United States)

    2011-09-29

    ... Prohibition on Circumvention of Copyright Protection Systems for Access Control Technologies, 68 FR 62011... Circumvention of Copyright Protection Systems for Access Control Technologies, 71 FR 68472, 68480, published in... Protection Systems for Access Control Technologies, 65 FR 64556, 64564, published in the Federal...

  17. 77 FR 25525 - Thirteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems.

    Science.gov (United States)

    2012-04-30

    ... Access Control Systems. AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems... Committee 224, Airport Security Access Control Systems DATES: The meeting will be held May 30, 2012, from...

  18. 77 FR 2343 - Eleventh Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2012-01-17

    ...). ACTION: Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY: The FAA..., Airport Security Access Control Systems. DATES: The meeting will be held February 9, 2012, from 10 a.m.-4..., Airport Security Access Control Systems. The agenda will include the following: February 9, 2012...

  19. Bluetooth Navigation System using Wi-Fi Access Points

    CERN Document Server

    Agrawal, Rohit

    2012-01-01

    There have been various navigation and tracking systems being developed with the help of technologies like GPS, GSM, Bluetooth, IR, Wi-Fi and Radar. Outdoor positioning systems have been deployed quite successfully using GPS but positioning systems for indoor environments still do not have widespread deployment due to various reasons. Most of these use only a single technology for positioning but using more than one in cooperation with each other is always advantageous for obtaining greater accuracy. Particularly, the ones which use Bluetooth are better since they would enhance the scalability of such a system because of the fact that this technology is in use by the common people so it would always be easy to track them. Moreover it would also reduce the hardware installation cost to some extent. The system that has been introduced here uses Bluetooth primarily for positioning and tracking in combination with Wi-Fi access points. The reason that makes the commercial application of such a system easier and ch...

  20. Multi-Channel SQUID System for MEG and Ultra-Low-Field MRI

    CERN Document Server

    Zotev, V S; Volegov, P L; Sandin, H J; Espy, M A; Mosher, J C; Urbaitis, A V; Newman, S G; Zotev, Vadim S.; Matlachov, Andrei N.; Volegov, Petr L.; Sandin, Henrik J.; Espy, Michelle A.; Mosher, John C.; Urbaitis, Algis V.; Newman, Shaun G.; Jr, Robert H. Kraus

    2007-01-01

    A seven-channel system capable of performing both magnetoencephalography (MEG) and ultra-low-field magnetic resonance imaging (ULF MRI) is described. The system consists of seven second-order SQUID gradiometers with 37 mm diameter and 60 mm baseline, having magnetic field resolution of 1.2-2.8 fT/rtHz. It also includes four sets of coils for 2-D Fourier imaging with pre-polarization. The system's MEG performance was demonstrated by measurements of auditory evoked response. The system was also used to obtain a multi-channel 2-D image of a whole human hand at the measurement field of 46 microtesla with 3 by 3 mm resolution.

  1. Feasibility study of contaminant detection for food with ULF-NMR/MRI system using HTS-SQUID

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukade, Yoshimi, E-mail: hatukade@ens.tut.ac.jp; Tsunaki, Shingo; Yamamoto, Masaaki; Abe, Takayuki; Hatta, Junichi; Tanaka, Saburo

    2013-11-15

    Highlights: •Feasibility of application of ultra-low field (ULF) NMR/MRI was studied. •ULF-NMR/MRI system utilized HTS-rf-SQUID and permanent magnet of 1.1 T. •Magnetic contaminants in water were successfully detected by NMR measurements. •Non-magnetic contaminants in water were distinguished by 1D-MRI measurements. -- Abstract: We have developed an ultra-low frequency (ULF) nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) system utilizing an HTS-SQUID for an application of contaminant detection in food and drink. In the system, a permanent magnet of 1.1 T was used to pre-polarize protons in a water sample. We measured NMR signals from water samples with or without various contaminants, such as stainless steel (SUS304), aluminum, and glass balls using the system. In the case that the contaminant was the SUS304 ball, the NMR signal intensity was reduced compared to that from the sample without the contaminant due to the remnant field of the contaminant. One-dimensional (1D) MRIs of the samples were also acquired to detect non-magnetic contaminants. In the 1D MRIs, changes of the MRI spectra were detected, corresponding to positions of the contaminants. These results show that the feasibility of the system to detect various contaminants in foods.

  2. Safety systems and access control in the National Ignition Facility.

    Science.gov (United States)

    Reed, Robert K; Bell, Jayce C

    2013-06-01

    The National Ignition Facility (NIF) is the world's largest and most energetic laser system. The facility has the potential to generate ionizing radiation due to the interaction between the laser beams and target material, with neutrons and gamma rays being produced during deuterium-tritium fusion reactions. To perform these experiments, several types of hazards must be mitigated and controlled to ensure personnel safety. NIF uses a real-time safety system to monitor and mitigate the hazards presented by the facility. The NIF facility Safety Interlock System (SIS) monitors for oxygen deficiency and controls access to the facility preventing exposure to laser light and radiation from the Radiation Generating Devices. It also interfaces to radiation monitoring and other radiological monitoring and alarm systems. The SIS controls permissives to the hazard-generating equipment and annunciates hazard levels in the facility. To do this reliably and safely, the SIS has been designed as a fail-safe system with a proven performance record now spanning over 10 y. This paper discusses the SIS, its design, implementation, operator interfaces, validation/verification, and the hazard mitigation approaches employed in the NIF. A brief discussion of the Failure Modes and Effect Analysis supporting the SIS will also be presented. The paper ends with a general discussion of SIS do's and don'ts and common design flaws that should be avoided in SIS design. PMID:23629061

  3. Fetal lung volume measurement by MRI with high-speed imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Osada, Hisao; Kaku, Kenshi [Chiba Univ. (Japan). Hospital

    2002-08-01

    Although ultrasonography is widely used for fetal morphologic observation, magnetic resonance imaging (MRI) has gained popularity as a new prenatal diagnostic method with recent introduction of high-speed imaging systems. Infants with lung hypoplasia affecting respiratory function require intensive management starting immediately after birth. Therefore, accurate prenatal differential diagnosis and severity evaluation are extremely important for these fetuses. The aim of this study is to measure fetal lung volume using a computer-based, three-dimensional MRI imaging system and to evaluate the possibility of clinical applications of this procedure. A total of 96 fetuses were evaluated, all were morphologically abnormal, and MRI was done for advanced assessment from 24 to 39 weeks gestation. Three-directional views of fetal chest were imaged by Signa Horizon, 1.5 Tesla, version 5.6 (General Electronics) with the following conditions; coil: TORSO coil, sequence: SSFSE (single shot fast spin echo), slice thickness: 5 mm, and imaging speed: 2 seconds/slice. To calculate the lung volume and create three-dimensional image, the lung area in each slice was traced out, then multiplied using computer image processing. Simultaneously, the volumes of all slices were summed to give the volume of each lung. Linear regression analysis and analysis of covariance (ANCOVA) were used for statistical analyses. In all cases, clear images were obtained, and were adequate for three-dimensional evaluation of the fetal lung. Thirty-five fetuses had poor outcomes, such as intrauterine fetal death, neonatal death, and intensive respiratory care. Regression lines of lung volume versus gestational week were calculated for these fetuses with poor outcome and 61 other fetuses with good outcome. ANCOVA, with gestational week as a covariant, revealed a significant intergroup difference in the lung volume (p<0.001). Similarly, regression lines of lung volume versus fetal body weight estimated by

  4. Fetal lung volume measurement by MRI with high-speed imaging systems

    International Nuclear Information System (INIS)

    Although ultrasonography is widely used for fetal morphologic observation, magnetic resonance imaging (MRI) has gained popularity as a new prenatal diagnostic method with recent introduction of high-speed imaging systems. Infants with lung hypoplasia affecting respiratory function require intensive management starting immediately after birth. Therefore, accurate prenatal differential diagnosis and severity evaluation are extremely important for these fetuses. The aim of this study is to measure fetal lung volume using a computer-based, three-dimensional MRI imaging system and to evaluate the possibility of clinical applications of this procedure. A total of 96 fetuses were evaluated, all were morphologically abnormal, and MRI was done for advanced assessment from 24 to 39 weeks gestation. Three-directional views of fetal chest were imaged by Signa Horizon, 1.5 Tesla, version 5.6 (General Electronics) with the following conditions; coil: TORSO coil, sequence: SSFSE (single shot fast spin echo), slice thickness: 5 mm, and imaging speed: 2 seconds/slice. To calculate the lung volume and create three-dimensional image, the lung area in each slice was traced out, then multiplied using computer image processing. Simultaneously, the volumes of all slices were summed to give the volume of each lung. Linear regression analysis and analysis of covariance (ANCOVA) were used for statistical analyses. In all cases, clear images were obtained, and were adequate for three-dimensional evaluation of the fetal lung. Thirty-five fetuses had poor outcomes, such as intrauterine fetal death, neonatal death, and intensive respiratory care. Regression lines of lung volume versus gestational week were calculated for these fetuses with poor outcome and 61 other fetuses with good outcome. ANCOVA, with gestational week as a covariant, revealed a significant intergroup difference in the lung volume (p<0.001). Similarly, regression lines of lung volume versus fetal body weight estimated by

  5. Chest MRI

    Science.gov (United States)

    Nuclear magnetic resonance - chest; Magnetic resonance imaging - chest; NMR - chest; MRI of the thorax; Thoracic MRI ... healthy enough to filter the contrast. During the MRI, the person who operates the machine will watch ...

  6. Real-time 3-dimensional virtual reality navigation system with open MRI for breast-conserving surgery

    International Nuclear Information System (INIS)

    We report here the early experiences using a real-time three-dimensional (3D) virtual reality navigation system with open magnetic resonance imaging (MRI) for breast-conserving surgery (BCS). Two patients with a non-palpable MRI-detected breast tumor underwent BCS under the guidance of the navigation system. An initial MRI for the breast tumor using skin-affixed markers was performed immediately prior to excision. A percutaneous intramammary dye marker was applied to delineate an excision line, and the computer software '3D Slicer' generated a real-time 3D virtual reality model of the tumor and the puncture needle in the breast. Under guidance by the navigation system, marking procedures were performed without any difficulties. Fiducial registration errors were 3.00 mm for patient no.1, and 4.07 mm for patient no.2. The real-time 3D virtual reality navigation system with open MRI is feasible for safe and accurate excision of non-palpable MRI-detected breast tumors. (author)

  7. LINEAR-DISPERSION DIVISION MULTIPLE-ACCESS FOR MIMO SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Deng Dan; Lv Xingzai; Zhu Jinkang

    2008-01-01

    Comprehensive study on novel Linear-Dispersion Division Multiple-Access (LDDMA) for multi-user uplink Multiple-Input Multiple-Output (MIMO) systems is proposed. In the new multi- plexing scheme, each user's information symbol is dispersed by a User-Specific Matrix (USM) both in space and time domain and linearly combined at base-station side. And a simple random search al- gorithm, based on capacity maximization criteria, is developed to generate a bank of USMs. Simulation results are presented to demonstrate the advantages of LDDMA. When the Bit Error Rate (BER) reaches 10, the performance gains are 3dB and 5dB, compared with Time-Division Linear Dispersion Codes (TD-LDC) and BLAST, respectively.

  8. Enhanced Role Based Access Control Mechanism for Electronic Examination System

    Directory of Open Access Journals (Sweden)

    Adebukola Onashoga

    2014-02-01

    Full Text Available Over the years, e-learning and e-examination has become standard in many institutions of higher learning. It has been observed that examination questions and results can be easily intercepted by invalid users, thus the security of resources shared among valid users is not guaranteed. In order to solve these problems as it relates to access control, a Role based Examination System (RBES was designed, developed and evaluated. RBES attempted to solve the security issue by the combination of two authentication techniques: text-based authentication and graphical password authentication. The Text-based authentication utilizes two text-based parameters namely the username and password. The graphical password authentication makes use of a finite set of controls (RBES chooses radio buttons which are identified by numbers. These numbers constitute the password used for graphical authentication. To improve on resource sharing among users in the examination system, RBES proposes role management (role creation, role update, role removal and user management (user creation, user update and user removal. The developed system made use of asp.net, C#, IIS server, WAMP server, Mysql and other tools for its development. RBES was tested by some legitimate and illegitimate users and the performance of the system was found to be satisfactory, hence RBES shows an efficient and reliable scheme that can be deployed in any examination or e-learning system. Finally the potential threats to the system were modeled and the use of weak passwords was found to be the most likely threat the system could be vulnerable to.

  9. MRI screening for breast cancer in women at high risk; is the Australian breast MRI screening access program addressing the needs of women at high risk of breast cancer?

    International Nuclear Information System (INIS)

    Breast magnetic resonance imaging (MRI) screening of women under 50 years old at high familial risk of breast cancer was given interim funding by Medicare in 2009 on the basis that a review would be undertaken. An updated literature review has been undertaken by the Medical Services Advisory Committee but there has been no assessment of the quality of the screening or other screening outcomes. This review examines the evidence basis of breast MRI screening and how this fits within an Australian context with the purpose of informing future modifications to the provision of Medicare-funded breast MRI screening in Australia. Issues discussed will include selection of high-risk women, the options for MRI screening frequency and measuring the outcomes of screening

  10. MRI screening for breast cancer in women at high risk; is the Australian breast MRI screening access program addressing the needs of women at high risk of breast cancer?

    Science.gov (United States)

    Schenberg, Tess; Mitchell, Gillian; Taylor, Donna; Saunders, Christobel

    2015-09-01

    Breast magnetic resonance imaging (MRI) screening of women under 50 years old at high familial risk of breast cancer was given interim funding by Medicare in 2009 on the basis that a review would be undertaken. An updated literature review has been undertaken by the Medical Services Advisory Committee but there has been no assessment of the quality of the screening or other screening outcomes. This review examines the evidence basis of breast MRI screening and how this fits within an Australian context with the purpose of informing future modifications to the provision of Medicare-funded breast MRI screening in Australia. Issues discussed will include selection of high-risk women, the options for MRI screening frequency and measuring the outcomes of screening. PMID:26451244

  11. MRI screening for breast cancer in women at high risk; is the Australian breast MRI screening access program addressing the needs of women at high risk of breast cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Schenberg, Tess [Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Familial Cancer Centre, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Mitchell, Gillian [Familial Cancer Centre, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria (Australia); Taylor, Donna [School of Surgery, University of Western Australia, Perth, Western Australia (Australia); Department of Radiology, Royal Perth Hospital, Perth, Western Australia (Australia); BreastScreen Western Australia, Adelaide Terrace, Perth, Western Australia (Australia); Saunders, Christobel [School of Surgery, University of Western Australia, Perth, Western Australia (Australia); Department of General Surgery, St John of God Hospital, Perth, Western Australia (Australia); Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia)

    2015-09-15

    Breast magnetic resonance imaging (MRI) screening of women under 50 years old at high familial risk of breast cancer was given interim funding by Medicare in 2009 on the basis that a review would be undertaken. An updated literature review has been undertaken by the Medical Services Advisory Committee but there has been no assessment of the quality of the screening or other screening outcomes. This review examines the evidence basis of breast MRI screening and how this fits within an Australian context with the purpose of informing future modifications to the provision of Medicare-funded breast MRI screening in Australia. Issues discussed will include selection of high-risk women, the options for MRI screening frequency and measuring the outcomes of screening.

  12. 78 FR 51810 - Twenty-Fourth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-08-21

    ... Security Access Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control... RTCA Special Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held...

  13. MRI and low back pain

    Science.gov (United States)

    Backache - MRI; Low back pain - MRI; Lumbar pain - MRI; Back strain - MRI; Lumbar radiculopathy - MRI; Herniated intervertebral disk - MRI; Prolapsed intervertebral disk - MRI; Slipped disk - MRI; Ruptured ...

  14. MRI screening for breast cancer in women at high risk; is the Australian breast MRI screening access program addressing the needs of women at high risk of breast cancer?

    OpenAIRE

    Schenberg, Tess; Mitchell, Gillian; Taylor, Donna; Saunders, Christobel

    2015-01-01

    Breast magnetic resonance imaging (MRI) screening of women under 50 years old at high familial risk of breast cancer was given interim funding by Medicare in 2009 on the basis that a review would be undertaken. An updated literature review has been undertaken by the Medical Services Advisory Committee but there has been no assessment of the quality of the screening or other screening outcomes. This review examines the evidence basis of breast MRI screening and how this fits within an Australi...

  15. A CAD system for assessment of MRI findings to track the progression of multiple sclerosis

    Science.gov (United States)

    Wong, Alexis; Gertych, Arkadiusz; Zee, Chi-Shing; Guo, Bing; Liu, Brent J.

    2007-03-01

    Multiple sclerosis (MS) is a progressive neurological disease affecting myelin pathways. MRI has become the medical imaging study of choice both for the diagnosis and for the follow-up and monitoring of multiple sclerosis. The progression of the disease is variable, and requires routine follow-up to document disease exacerbation, improvement, or stability of the characteristic MS lesions or plaques. The difficulties with using MRI as a monitoring tool are the significant quantities of time needed by the radiologist to actually measure the size of the lesions, and the poor reproducibility of these manual measurements. A CAD system for automatic image analysis improves clinical efficiency and standardizes the lesion measurements. Multiple sclerosis is a disease well suited for automated analysis. The segmentation algorithm devised classifies normal and abnormal brain structures and measures the volume of multiple sclerosis lesions using fuzzy c-means clustering with incorporated spatial (sFCM) information. First, an intracranial structures mask in T1 image data is localized and then superimposed in FLAIR image data. Next, MS lesions are identified by sFCM and quantified within a predefined volume. The initial validation process confirms a satisfactory comparison of automatic segmentation to manual outline by a neuroradiologist and the results will be presented.

  16. The development of an MRI lesion quantifying system for multiple sclerosis patients undergoing treatment

    Science.gov (United States)

    Moin, Paymann; Ma, Kevin; Amezcua, Lilyana; Gertych, Arkadiusz; Liu, Brent

    2009-02-01

    Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that affects approximately 2.5 million people worldwide. Magnetic resonance imaging (MRI) is an established tool for the assessment of disease activity, progression and response to treatment. The progression of the disease is variable and requires routine follow-up imaging studies. Currently, MRI quantification of multiple sclerosis requires a manual approach to lesion measurement and yields an estimate of lesion volume and interval change. In the setting of several prior studies and a long treatment history, trends related to treatment change quickly become difficult to extrapolate. Our efforts seek to develop an imaging informatics based MS lesion computer aided detection (CAD) package to quantify and track MS lesions including lesion load, volume, and location. Together, with select clinical parameters, this data will be incorporated into an MS specific e- Folder to provide decision support to evaluate and assess treatment options for MS in a manner tailored specifically to an individual based on trends in MS presentation and progression.

  17. Whole-body MRI in children with Langerhans cell histiocytosis for the evaluation of the skeletal system

    International Nuclear Information System (INIS)

    Purpose: the usefulness of whole-body MRI (WB-MRI) for the detection of skeletal lesions in patients with Langerhans cell histiocytosis should be documented on the basis of case presentations. Materials and methods: in six patients with histologically proven Langerhans cell histiocytosis, 14 WB-MRI examinations were performed to evaluate the skeletal system within disease staging (6 primary, 8 follow-up examinations). The examinations were performed on a 1.5 Tesla, 32-channel whole-body scanner. The examination protocol consisted of T1-weighted and STIR sequences in coronal and sagittal orientation. For comparison, radiographs of the initial skeletal lesions and those that were additionally detected on WB-MRI were available. Results: in 4 patients no additional skeletal lesions were found on WB-MRI besides the initial lesion leading to the diagnosis of unifocal single system disease. In 2 patients WB-MRI was able to identify additional skeletal lesions. In a 5 1/2 year-old boy with the primary lesion located in the cervical spine, a second lesion was detected in the lumbar spine on the initial scan and in the skull and proximal femur during follow-up examination. In a 12 year-old girl with a primary lesion of the thoracic spine, WB-MRI diagnosed additional lesions in the pelvic bone and the tibia. In both patients the diagnosis of multifocal skeletal involvement led to chemotherapy. During follow-up examination, the healing response under therapy could be demonstrated. Comparison with conventional imaging showed that especially lesions located in the spine or the pelvis were not detectable on radiographs even when knowing the MR results. (orig.)

  18. MRI in psychiatry

    Energy Technology Data Exchange (ETDEWEB)

    Mulert, Christoph [UKE, Hamburg (Germany). Psychiatry Neuroimaging Branch; Shenton, Martha E. (ed.) [Harvard Medical School, Boston, MA (United States). Dept. of Psychiatry and Radiology

    2014-07-01

    This is the first comprehensive textbook on the use of MRI in psychiatry covering imaging techniques, brain systems and a review of findings in different psychiatric disorders. The book is divided into three sections, the first of which covers in detail all the major MRI-based methodological approaches available today, including fMRI, EEG-fMRI, DTI, and MR spectroscopy. In addition, the role of MRI in imaging genetics and combined brain stimulation and imaging is carefully explained. The second section provides an overview of the different brain systems that are relevant for psychiatric disorders, including the systems for perception, emotion, cognition, and reward. The final part of the book presents the MRI findings that are obtained in all the major psychiatric disorders using the previously discussed techniques. Numerous carefully chosen images support the informative text, making this an ideal reference work for all practitioners and trainees with an interest in this flourishing field.

  19. Compact Wireless Access Nodes for WDM Bidirectional Radio-over-Fiber System Based on RSOA

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact.......We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact....

  20. An Automated and Intelligent Medical Decision Support System for Brain MRI Scans Classification.

    Directory of Open Access Journals (Sweden)

    Muhammad Faisal Siddiqui

    Full Text Available A wide interest has been observed in the medical health care applications that interpret neuroimaging scans by machine learning systems. This research proposes an intelligent, automatic, accurate, and robust classification technique to classify the human brain magnetic resonance image (MRI as normal or abnormal, to cater down the human error during identifying the diseases in brain MRIs. In this study, fast discrete wavelet transform (DWT, principal component analysis (PCA, and least squares support vector machine (LS-SVM are used as basic components. Firstly, fast DWT is employed to extract the salient features of brain MRI, followed by PCA, which reduces the dimensions of the features. These reduced feature vectors also shrink the memory storage consumption by 99.5%. At last, an advanced classification technique based on LS-SVM is applied to brain MR image classification using reduced features. For improving the efficiency, LS-SVM is used with non-linear radial basis function (RBF kernel. The proposed algorithm intelligently determines the optimized values of the hyper-parameters of the RBF kernel and also applied k-fold stratified cross validation to enhance the generalization of the system. The method was tested by 340 patients' benchmark datasets of T1-weighted and T2-weighted scans. From the analysis of experimental results and performance comparisons, it is observed that the proposed medical decision support system outperformed all other modern classifiers and achieves 100% accuracy rate (specificity/sensitivity 100%/100%. Furthermore, in terms of computation time, the proposed technique is significantly faster than the recent well-known methods, and it improves the efficiency by 71%, 3%, and 4% on feature extraction stage, feature reduction stage, and classification stage, respectively. These results indicate that the proposed well-trained machine learning system has the potential to make accurate predictions about brain abnormalities

  1. An Automated and Intelligent Medical Decision Support System for Brain MRI Scans Classification.

    Science.gov (United States)

    Siddiqui, Muhammad Faisal; Reza, Ahmed Wasif; Kanesan, Jeevan

    2015-01-01

    A wide interest has been observed in the medical health care applications that interpret neuroimaging scans by machine learning systems. This research proposes an intelligent, automatic, accurate, and robust classification technique to classify the human brain magnetic resonance image (MRI) as normal or abnormal, to cater down the human error during identifying the diseases in brain MRIs. In this study, fast discrete wavelet transform (DWT), principal component analysis (PCA), and least squares support vector machine (LS-SVM) are used as basic components. Firstly, fast DWT is employed to extract the salient features of brain MRI, followed by PCA, which reduces the dimensions of the features. These reduced feature vectors also shrink the memory storage consumption by 99.5%. At last, an advanced classification technique based on LS-SVM is applied to brain MR image classification using reduced features. For improving the efficiency, LS-SVM is used with non-linear radial basis function (RBF) kernel. The proposed algorithm intelligently determines the optimized values of the hyper-parameters of the RBF kernel and also applied k-fold stratified cross validation to enhance the generalization of the system. The method was tested by 340 patients' benchmark datasets of T1-weighted and T2-weighted scans. From the analysis of experimental results and performance comparisons, it is observed that the proposed medical decision support system outperformed all other modern classifiers and achieves 100% accuracy rate (specificity/sensitivity 100%/100%). Furthermore, in terms of computation time, the proposed technique is significantly faster than the recent well-known methods, and it improves the efficiency by 71%, 3%, and 4% on feature extraction stage, feature reduction stage, and classification stage, respectively. These results indicate that the proposed well-trained machine learning system has the potential to make accurate predictions about brain abnormalities from the

  2. "What Page, Miss?" Enhancing Text Accessibility with DAISY (Digital Accessible Information SYstem)

    Science.gov (United States)

    Spooner, Sue

    2014-01-01

    Introduction: The provision of specially formatted materials is a complex and increasingly difficult task, given the extensive and burgeoning range of texts and resources available for classroom use. The need to extend the provision of accessible formats to include digital resources (in addition to braille, audio, and large print) led to a study…

  3. Software interface system for Geophysical Data Access and Management System (GPDAMS-CD)

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.

    -friendly access to large volume of data and means to visualize and extract selected data as per need. The software requires a minimum of computing expertise as it is controlled by a system of `pull down' menus, backed up by a context-sensitive system...

  4. SINP space physics data storage and access system

    Science.gov (United States)

    Barinova, Vera; Kalegaev, Vladimir; Parunakian, David

    In this paper we present the system for automated data retrieval and processing developed in the the Skobeltsyn Institute of Nuclear Physics. Telemetry data files containing scientific information (e.g. charged particle fluxes) are auto-matically parsed and stored in our Oracle database immediately upon arrival. Parsed telemetry files, metadata, instrument technical information and orbital parameters are also stored. Most of the data can be accessed via our public FTP server. Users can preview the data available for time intervals and channels of interest using the web interface provided. The preview plot building software has also been developed in-house. This system has been successfully used in 2009 with the following spacecraft and instru-ments: Electron-M-Pesca at Coronas-Photon (Electrons 200KeV -4 MeV+; Protons : 4 MeV -80MeV+ ;α : 5 -24 MeV/nucleon; CNO : 6 -15MeV/nucleon), DUFIK at Tatiana-2 (electrons, infrared 600nm ¡ ¡ 700nm and ultraviolet 300nm ¡ ¡ 400nm), MSGI and SKL at Meteor-M (10 spectral channels: 0,5-12,5 µm ). The data collections are available at http://smdc.sinp.msu.ru for visual preview and download.

  5. A system for success: BMC Systems Biology, a new open access journal

    OpenAIRE

    Webb Penelope A; Hodgkinson Matt J

    2007-01-01

    Abstract BMC Systems Biology is the first open access journal spanning the growing field of systems biology from molecules up to ecosystems. The journal has launched as more and more institutes are founded that are similarly dedicated to this new approach. BMC Systems Biology builds on the ongoing success of the BMC series, providing a venue for all sound research in the systems-level analysis of biology.

  6. A system for success: BMC Systems Biology, a new open access journal

    Directory of Open Access Journals (Sweden)

    Webb Penelope A

    2007-09-01

    Full Text Available Abstract BMC Systems Biology is the first open access journal spanning the growing field of systems biology from molecules up to ecosystems. The journal has launched as more and more institutes are founded that are similarly dedicated to this new approach. BMC Systems Biology builds on the ongoing success of the BMC series, providing a venue for all sound research in the systems-level analysis of biology.

  7. Simultaneous fMRI-PET of the opioidergic pain system in human brain

    DEFF Research Database (Denmark)

    Wey, Hsiao-Ying; Catana, Ciprian; Hooker, Jacob M;

    2014-01-01

    MRI and PET provide complementary information for studying brain function. While the potential use of simultaneous MRI/PET for clinical diagnostic and disease staging has been demonstrated recently; the biological relevance of concurrent functional MRI-PET brain imaging to dissect neurochemically...... and striatum related to pain processing, while modality specific brain networks were also found. Co-localized fMRI and PET signal changes in the thalamus were positively correlated suggesting that pain-induced changes in opioid neurotransmission contribute a significant component of the fMRI signal...... change in this region. Simultaneous fMRI-PET provides unique opportunities allowing us to relate specific neurochemical events to functional hemodynamic activation and to investigate the impacts of neurotransmission on neurovascular coupling of the human brain in vivo....

  8. The role of CRIS systems in measuring Open Access publications

    NARCIS (Netherlands)

    Scharnhorst, A.M.; Dijk, E.M.S.; Doorn, P.K.; van Berchum, M.

    2016-01-01

    Open Access to scientific results - from publications to data - is high on the agenda of science policy drivers. Since long there is no doubt that making your own research available on the web is the best way to gain visibility and impact (Lawrence 2001). The Open Access movement started with calls

  9. Single port access surgery with a novel Port Camera system.

    Science.gov (United States)

    Terry, Benjamin S; Schoen, Jonathan; Mills, Zachary; Rentschler, Mark E

    2012-06-01

    In this work, the authors designed, built, and tested a novel port camera system for single port access (SPA) laparoscopic surgery. This SPA Port Camera device integrates the monitor, laparoscopic camera, and light source into an inexpensive, portable cannula port. The device uses a 2-channel SPA port inserted through an umbilical incision, similar to traditional SPA. After insertion into a channel, the device deploys a small camera module and LED lamp in vivo. An integrated, on-patient LCD provides the view of the surgical site. The design intent of the port camera is to enhance SPA by (a) reducing the size of the SPA port through the elimination of the dedicated laparoscope channel; (b) reducing equipment cost by integrating an inexpensive CMOS sensor and LED lamp at the port tip; (c) eliminating the need for an assistant who operates the laparoscope; and (d) mechanically coupling the camera, tool port, and on-patient LCD screen. The effectiveness of the device was evaluated by comparing the video performance with a leading industry laparoscope and by performing a user evaluation study and live porcine surgery with the device. Effectiveness of the device was mixed. Overall video system performance of the device is better than an industry standard high-definition laparoscope, implying that significant cost savings over a traditional system are possible. Participant study results suggest that simulated laparoscopic tasks are as efficient with the SPA Port Camera as they are with a typical SPA configuration. However, live surgery revealed several shortcomings of the SPA Port Camera.

  10. Ultra-sensitive molecular MRI of cerebrovascular cell activation enables early detection of chronic central nervous system disorders

    International Nuclear Information System (INIS)

    Since endothelial cells can be targeted by large contrast-carrying particles, molecular imaging of cerebrovascular cell activation is highly promising to evaluate the underlying inflammation of the central nervous system (CNS). In this study, we aimed to demonstrate that molecular magnetic resonance imaging (MRI) of cerebrovascular cell activation can reveal CNS disorders in the absence of visible lesions and symptoms. To this aim, we optimized contrast carrying particles targeting vascular cell adhesion molecule-1 and MRI protocols through both in vitro and in vivo experiments. Although, pre-contrast MRI images failed to reveal the ongoing pathology, contrast-enhanced MRI revealed hypoperfusion-triggered CNS injury in vascular dementia, unmasked amyloid-induced cerebrovascular activation in Alzheimer's disease and allowed monitoring of disease activity during experimental autoimmune encephalomyelitis. Moreover, contrast-enhanced MRI revealed the cerebrovascular cell activation associated with known risk factors of CNS disorders such as peripheral inflammation, ethanol consumption, hyperglycemia and aging. By providing a dramatically higher sensitivity than previously reported methods and molecular contrast agents, the technology described in the present study opens new avenues of investigation in the field of neuro-inflammation. (authors)

  11. Universal remote access infrastructure for embedded systems; Universelle Fernzugriff-Infrastruktur fuer eingebettete Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Jazdi, N. [Stuttgart Univ. (Germany). Inst. fuer Automatisierungs- und Softwaretechnik

    2005-07-01

    This article describes a flexible and extensible infrastructure for applying Web-Technologies to embedded systems.The presented approach develops a Three-level-Architecture consisting of the embedded system, the universal Remote-Access-Server and the Remote-Access-Client. A system-spanning general interface allows the binding of embedded systems in order to access their process data. Additionally, this procedure facilitates a flexible processing of the device data, so that it is ready to be used by different control devices. To ensure flexibility - connecting different devices on the one side and providing information for different clients like PC, PDA or mobile phone on the other side - a new XML-based description language (Service Description Markup Language - SDML) is introduced. The SDML documents contain information about connected embedded systems, reusable device data and the presentation policies for different clients. These documents are specifically created for each device. Applying the suggested procedure, different embedded systems can be connected to the Internet with minimum hardware and software requirements/costs. Software components of the Remote-Access-Server, once developed, can be used and applied to various devices which lead to a reduction of the development costs. The user can use an ordinary web browser to communicate with the devices and does not need to install any additional software on his local computer. (orig.) (orig.)

  12. A new MRI grading system for cervical foraminal stenosis based on axial T2-weighted images

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Jin; Lee, Joon Woo; Seo, Ji Woon; Kang, Heung Sik [Dept. of Radiology, , Seoul National University Bundang Hospital, Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul National University Medical Research Center, Seongnam (Korea, Republic of); Chai, Jee Won [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Yoo, Hye Jin; Kang, Yu Suhn [Dept. of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Ahn, Joong Mo [Dept. of Radiology, University of Pittsburgh Medical Center, Pittsburgh (United States)

    2015-12-15

    The purpose of this study was to evaluate the reliability of a new magnetic resonance imaging (MRI) grading system for cervical neural foraminal stenosis (NFS). Cervical NFS at bilateral C4/5, C5/6, and C6/7 was classified into the following three grades based on the T2-weighted axial images: Grade 0 = absence of NFS, with the narrowest width of the neural foramen greater than the width of the extraforaminal nerve root (EFNR); Grade 1 = the narrowest width of the neural foramen the same or less than (but more than 50% of) the width of the EFNR; Grade 2 = the width of the neural foramen the same or less than 50% of the width of the EFNR. The MRIs of 96 patients who were over 60 years old (M:F = 50:46; mean age 68.4 years; range 61-86 years) were independently analyzed by seven radiologists. Interobserver and intraobserver agreements were analyzed using the percentage agreement, kappa statistics, and intraclass correlation coefficient (ICC). For the distinction among the three individual grades at all six neural foramina, the ICC ranged from 0.68 to 0.73, indicating fair to good reproducibility. The percentage agreement ranged from 60.2% to 70.6%, and the kappa values (κ = 0.50-0.58) indicated fair to moderate agreement. The percentages of intraobserver agreement ranged from 85.4% to 93.8% (κ = 0.80-0.92), indicating near perfect agreement. The new MRI grading system shows sufficient interobserver and intraobserver agreement to reliably assess cervical NFS.

  13. The Time Between: Continuously-defined accessibility functions for schedule-based transportation systems

    OpenAIRE

    Paul Anderson; Andrew Owen; David Levinson

    2012-01-01

    Accessibility is traditionally considered to be a property of a point or region in space, and to be invariant over time (or at least over some computationally convenient time interval). How- ever, a locations accessibility can vary over time on a wide range of scales. This temporal variation is especially significant for schedule-based transportation systems. Current measures of accessibility generally reflect the accessibility only at points in time corresponding to the departures of one or ...

  14. Database Security System for Applying Sophisticated Access Control via Database Firewall Server

    OpenAIRE

    Eun-Ae Cho; Chang-Joo Moon; Dae-Ha Park; Kang-Bin Yim

    2014-01-01

    Database security, privacy, access control, database firewall, data break masking Recently, information leakage incidents have occurred due to database security vulnerabilities. The administrators in the traditional database access control methods grant simple permissions to users for accessing database objects. Even though they tried to apply more strict permissions in recent database systems, it was difficult to properly adopt sophisticated access control policies to commercial databases...

  15. An Efficient Role and Object Based Access Control Model Implemented in a PDM System

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiaowen; TAN Jian; HUANG Xiangguo

    2006-01-01

    An effective and reliable access control is crucial to a PDM system. This article has discussed the commonly used access control models, analyzed their advantages and disadvantages, and proposed a new Role and Object based access control model that suits the particular needs of a PDM system. The new model has been implemented in a commercial PDM system, which has demonstrated enhanced flexibility and convenience.

  16. Task-role-based Access Control Model in Smart Health-care System

    Directory of Open Access Journals (Sweden)

    Wang Peng

    2015-01-01

    Full Text Available As the development of computer science and smart health-care technology, there is a trend for patients to enjoy medical care at home. Taking enormous users in the Smart Health-care System into consideration, access control is an important issue. Traditional access control models, discretionary access control, mandatory access control, and role-based access control, do not properly reflect the characteristics of Smart Health-care System. This paper proposes an advanced access control model for the medical health-care environment, task-role-based access control model, which overcomes the disadvantages of traditional access control models. The task-role-based access control (T-RBAC model introduces a task concept, dividing tasks into four categories. It also supports supervision role hierarchy. T-RBAC is a proper access control model for Smart Health-care System, and it improves the management of access rights. This paper also proposes an implementation of T-RBAC, a binary two-key-lock pair access control scheme using prime factorization.

  17. A United Access Control Model for Systems in Collaborative Commerce

    OpenAIRE

    Ruo-Fei Han; Hou-Xiang Wang; Qian Xiao; Xiao-Pei Jing; Hui Li

    2009-01-01

    The latest researches on access control model are dramatically different from conventional ones. Nowadays, most attention is paid to accessing across organizational boundaries. So, how to identify the applicant and determine authorization with limited information; how to express and exchange control rules expediently; how to protect confidential information and enhance collaboration simultaneously, are the most concerned problems. However, for large commercial organizations, a fine management...

  18. Presidential Management Fellows (PMF) Talent Acquisition System, PMF-TAS (ACCESS CONTROLLED)

    Data.gov (United States)

    Office of Personnel Management — Application and Assessment system for Presidential Management Fellows (PMF) and PMF Science, Technology, Engineering, and Math (STEM) programs. This sytem is access...

  19. 48 CFR 504.602-71 - Federal Procurement Data System-Public access to data.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Federal Procurement Data System-Public access to data. 504.602-71 Section 504.602-71 Federal Acquisition Regulations System GENERAL SERVICES ADMINISTRATION GENERAL ADMINISTRATIVE MATTERS Contract Reporting 504.602-71 Federal Procurement Data System—Public access to data....

  20. From System Expansion to System Contraction: Access to Higher Education in Poland

    Science.gov (United States)

    Kwiek, Marek

    2013-01-01

    Access to higher education in Poland is changing due to the demography of smaller cohorts of potential students. Following a demand-driven educational expansion after the collapse of communism in 1989, the higher education system is now contracting. Such expansion/contraction and growth/decline in European higher education has rarely been…

  1. Comparative Evaluation of Diagnostic Value of Prenatal USG and MRI in the Diagnosis of Fetal Central Nervous System Defects

    Directory of Open Access Journals (Sweden)

    I. Herman-Sucharska

    2011-05-01

    Full Text Available Background/Objective: The purpose of the study was"nto compare the diagnostic values of prenatal ultrasound"nand MRI in fetal central nervous system defects."nPatients and Methods: Three-hundred eighty-five"nMRIs were performed in pregnant women with the"nultrasound suspicion of fetal defect. US was conducted"nwith the Voluson-Kretz730PRO. In 158 cases (41%"nfetal CNS defect was found. MR was performed with the"n1.5T system, torso surface coil, SSFSET2 sequence. MR"nresults were compared with prenatal US and verified"nafter the delivery by physical tests, US, TK and surgery"nor in cases of infant death with a pathomorphological"nexamination."nResults: Of 158 infants, eight died after delivery, 93 were"nconsulted in the neurosurgical clinic, 19 underwent a"nneurosurgery treatment and the remaining seven infants'"nfate is unknown. Fetal MRI widened the pertinent US"ndiagnoses in 62%. The 100% compliance is pertained"nto hydrocephalus and anencephaly. US results failed"nin some cases of corpus callosum agenesis, aqueductal"nstenosis, intracranial cyst, holoprosencephaly,"nschizencephaly, Dandy-Walker complex, syringomyelia,"ndiplomyelia and myelomeningocele. In 15 cases, MRI"ncompletely changed the prognosis and treatment"n(holoprosencephaly, myelomeningocoele, diplomyelia,"nintracranial cyst, lung hypoplasia, urinary bladder"nagenesis-not detected during prenatal US. Postnatal"nexaminations and surgery confirmed the results of"nprenatal MRI."nConclusion: MRI compared with prenatal US proved"nbetter effectiveness in imaging of fetal CNS defects,"nespecially in the imaging of the posterior fossa structures,"nthe ventricular system, the corpus callosum, the"nevaluation of meningocoele contents and the complex"nmalformations of the central nervous system.

  2. Getting an MRI

    Medline Plus

    Full Text Available ... Dictionary of Medical Words En Español What Other Kids Are Reading Movie: Digestive System Winter Sports: Sledding, ... a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A ...

  3. H-RBAC: A Hierarchical Access Control Model for SaaS Systems

    Directory of Open Access Journals (Sweden)

    Dancheng Li

    2011-08-01

    Full Text Available SaaS is a new way to deploy software as a hosted service and accessed over the Internet which means the customers don’t need to maintain the software code and data on their own servers. So it’s more important for SaaS systems to take security issues into account. Access control is a security mechanism that enables an authority to access to certain restricted areas and resources according to the permissions assigned to a user. Several access models have been proposed to realize the access control of single instance systems. However, most of the existing models couldn’t address the following SaaS system problems: (1 role name conflicts (2 cross-level management (3 the isomerism of tenants' access control (4 temporal delegation constraints. This paper describes a hierarchical RBAC model called H-RBAC solves all the four problems of SaaS systems mentioned above. This model addresses the SaaS system access control in both system level and tenant level. It combines the advantages of RBDM and ARBAC97 model and introduces temporal constraints to SaaS access control model. In addition, a practical approach to implement the access control module for SaaS systems based on H-RBAC model is also proposed in this paper.

  4. Dynamic MRI-based computer aided diagnostic systems for early detection of kidney transplant rejection: A survey

    Science.gov (United States)

    Mostapha, Mahmoud; Khalifa, Fahmi; Alansary, Amir; Soliman, Ahmed; Gimel'farb, Georgy; El-Baz, Ayman

    2013-10-01

    Early detection of renal transplant rejection is important to implement appropriate medical and immune therapy in patients with transplanted kidneys. In literature, a large number of computer-aided diagnostic (CAD) systems using different image modalities, such as ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT), and radionuclide imaging, have been proposed for early detection of kidney diseases. A typical CAD system for kidney diagnosis consists of a set of processing steps including: motion correction, segmentation of the kidney and/or its internal structures (e.g., cortex, medulla), construction of agent kinetic curves, functional parameter estimation, diagnosis, and assessment of the kidney status. In this paper, we survey the current state-of-the-art CAD systems that have been developed for kidney disease diagnosis using dynamic MRI. In addition, the paper addresses several challenges that researchers face in developing efficient, fast and reliable CAD systems for the early detection of kidney diseases.

  5. Evaluating the Accessibility of Three Open-Source Learning Content Management Systems: A Comparative Study

    OpenAIRE

    Iglesias, Ana; Moreno, Lourdes; Martínez, Paloma; Calvo, Rocío

    2011-01-01

    Learning content management systems (LCMSs) have become increasingly popular in the educational field over the past few years. However, problems in system design can create difficulties in the interactions between LCMSs and an important sector of the user population. The assessment and monitoring of LCMS accessibility are vital for the guarantee of universal accessibility in education. This article presents a comparative study of the accessibility of three web-based, open-source L...

  6. The entire network topology display system of terminal communication access network

    OpenAIRE

    An Yi

    2016-01-01

    Now order terminal communication access network is network technology in Shanxi Province is diversiform, device type complex, lack of unified technical standard, the terminal communication access network management system of construction constitutes a great obstacle. Need to build a “unified communication interface and communication standard, unified communications network management” of the terminal communication access network cut in the integrated network management system, for the termina...

  7. Accessibility od design documentation on mobile devices with Android Operating System

    OpenAIRE

    Lovše, Tilen

    2013-01-01

    In this graduation thesis the accessibility of design documentation on mobile devices with Android operating system is discussed. Mobile devices, used for accessing to design documentation, are tablet computers or simply tablets. Introduction presents benefits of accessing to design documentation on tablets and Slovenian history in this field, followed by the review of Android operating system, its history, upgrade and features. Practical part covers the review of five different tablets, whic...

  8. MRI Scans

    Science.gov (United States)

    Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from ...

  9. MRI-based motion correction of thoracic PET: initial comparison of acquisition protocols and correction strategies suitable for simultaneous PET/MRI systems

    Energy Technology Data Exchange (ETDEWEB)

    Dikaios, Nikolaos; Fryer, Tim D. [University of Cambridge, Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, Cambridge (United Kingdom); Izquierdo-Garcia, David; Mani, Venkatesh; Fayad, Zahi A. [Mount Sinai School of Medicine, Imaging Science Laboratories, Translational and Molecular Imaging Institute, Department of Radiology, New York, NY (United States); Graves, Martin J. [University of Cambridge, Department of Radiology, Cambridge (United Kingdom)

    2012-02-15

    Magnetic resonance imaging (MRI) acquired on equipment capable of simultaneous MRI and positron emission tomography (PET) could potentially provide the gold standard method for motion correction of PET. To assess the latter, in this study we compared fast 2D and 3D MRI of the torso and used deformation parameters from real MRI data to correct simulated PET data for respiratory motion. PET sinogram data were simulated using SimSET from a 4D pseudo-PET image series created by segmenting MR images acquired over a respiratory cycle. Motion-corrected PET images were produced using post-reconstruction registration (PRR) and motion-compensated image reconstruction (MCIR). MRI-based motion correction improved PET image quality at the lung-liver and lung-spleen boundaries and in the heart but little improvement was obtained where MRI contrast was low. The root mean square error in SUV units per voxel compared to a motion-free image was reduced from 0.0271 (no motion correction) to 0.0264 (PRR) and 0.0250 (MCIR). Motion correction using MRI can improve thoracic PET images but there are limitations due to the quality of fast MRI. (orig.)

  10. Validation of an anatomical coordinate system for clinical evaluation of the knee joint in upright and closed MRI.

    Science.gov (United States)

    Olender, Gavin; Hurschler, Christof; Fleischer, Benjamin; Friese, Karl-Ingo; Sukau, Andreas; Gutberlet, Marcel; Becher, Christoph

    2014-05-01

    A computerized method to automatically and spatially align joint axes of in vivo knee scans was established and compared to a fixed reference system implanted in a cadaver model. These computational methods to generate geometric models from static MRI images with an automatic coordinate system fitting proved consistent and accurate to reproduce joint motion in multiple scan positions. Two MRI platforms, upright and closed, were used to scan a phantom cadaver knee to create a three-dimensional, geometric model. The knee was subsequently scanned in several positions of knee bending in a custom made fixture. Reference markers fixed to the bone were tracked by an external infrared camera system as well as by direct segmentation from scanned images. Anatomical coordinate systems were automatically fitted to the segmented bone model and the transformations of joint position were compared to the reference marker coordinate systems. The tracked translation and rotation measurements of the automatic coordinate system were found to be below root mean square errors of 0.8 mm and 0.7°. In conclusion, the precision of the translation and rotational tracking is found to be sensitive to the scanning modality, albeit in upright or closed MRI, but still within comparative measures to previously performed studies. The potential to use segmented bone models for patient joint analysis could vastly improve clinical evaluation of disorders of the knee with continual application in future three-dimensional computations.

  11. 77 FR 71474 - Seventeenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2012-11-30

    ...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held December 13, 2012... Federal Aviation Administration Seventeenth Meeting: RTCA Special Committee 224, Airport Security...

  12. 78 FR 43963 - Twenty-Third Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-07-22

    ...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held on June 20, 2013... Federal Aviation Administration Twenty-Third Meeting: RTCA Special Committee 224, Airport Security...

  13. 77 FR 64838 - Sixteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2012-10-23

    ...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held November 15, 2012... Federal Aviation Administration Sixteenth Meeting: RTCA Special Committee 224, Airport Security...

  14. 78 FR 16757 - Twentieth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-03-18

    ...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held April 4, 2013 from 9... Federal Aviation Administration Twentieth Meeting: RTCA Special Committee 224, Airport Security...

  15. 78 FR 31627 - Twenty-Second Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-05-24

    ...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held on June 20, 2013... Federal Aviation Administration Twenty-Second Meeting: RTCA Special Committee 224, Airport Security...

  16. 78 FR 7850 - Nineteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-02-04

    ...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held February 21, 2013... Federal Aviation Administration Nineteenth Meeting: RTCA Special Committee 224, Airport Security...

  17. 77 FR 55894 - Fifteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2012-09-11

    ...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems DATES: The meeting will be held September 27-28, 2012... Federal Aviation Administration Fifteenth Meeting: RTCA Special Committee 224, Airport Security...

  18. 78 FR 22025 - Twenty First Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Science.gov (United States)

    2013-04-12

    ...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held April 9-10, 2013... Federal Aviation Administration Twenty First Meeting: RTCA Special Committee 224, Airport Security...

  19. Upper bound for energy efficiency in multi-cell fibre-wireless access systems

    DEFF Research Database (Denmark)

    Koonen, A.M.J.; Popov, M.; Wessing, Henrik

    2013-01-01

    Bringing radio access points closer to the end-users improves radio energy efficiency. However, taking into account both the radio and the optical parts of a fibre-wireless access system, the overall system energy efficiency has an upper bound determined by the relation between the energy...

  20. Upper Bound for Energy Efficiency in Multi-Cell Fibre-Wireless Access Systems

    DEFF Research Database (Denmark)

    Koonen, A. M. J.; Popov, M.; Wessing, Henrik

    Bringing radio access points closer to the end-users improves radio energy efficiency. However, taking into account both the radio and the optical parts of a fibre-wireless access system, the overall system energy efficiency has an upper bound determined by the relation between the energy...

  1. MRI scanner variability studies using a semi-automated analysis system.

    Science.gov (United States)

    Hyde, R J; Ellis, J H; Gardner, E A; Zhang, Y; Carson, P L

    1994-01-01

    Due to the unique design of the Parallel Rod Test Object (PRoTO) and the associated semi-automated analysis program, it was necessary to test it extensively for precision and accuracy, and preliminarily for utility, before its distribution for wider use in MRI system quality control (QC). The test object and analysis program measured the desired quantities reproducibly and they accurately measured predicted changes from intentionally adjusted imaging system parameters, yielding sensitivity of the various test measures to deviation in the system operating parameters. From a single scan of the most recent revision of the test object, multiple quantitative quality control measures were obtained throughout the scanning volume on two MR imaging systems over periods of six and twelve months, respectively. From these and earlier trials, an initial indication was obtained of which performance measures are worth monitoring for QC. This experience suggests that signal-to-noise ratio (SNR) and distortion (including display scale) should be monitored but not necessarily the resolution. The latter was only found to alter at the same time or later than other parameters such as SNR had changed. Slice thickness was found to vary on some units and this measure was also used in normalizing the SNR by voxel volume. SNR, distortion, and resolution measurements using field-echo sequences were less stable than those using spin-echo sequences. Use of this QC program to test a wide variety of image quality measures allowed timely assessment of the long-term variability of the units tested. Long-term variability may become among the most important measures for comparison of system performance and maintenance.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7997096

  2. Study of LANs access technologies in wind power system

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    2010-01-01

    techniques are addressed individually for each layer. Because of the particularity of the offshore wind farm, the communication network of the offshore wind farm may be treated as a LAN. Therefore the popular LANs access techniques, including Ethernet, at the Data Link Layer of the ISO seven-layers in wind...

  3. Physical protection of hardware and software. Linking access control systems with operational computer systems

    International Nuclear Information System (INIS)

    The existence and use of software and networks have generated another possibility for perpetrators to influence systems in nuclear facilities or to prepare malevolent acts. Data security has become an element of physical protection plans, not as an end in itself but as a means to achieve physical protection objectives. Physical protection measures are additional measures, which become necessary when other measures that have to be taken (e.g. in compliance with international standards) are insufficient to prevent a hazard to the protection goals through data manipulation by software and hardware. In planning or assessing data protection measures for the purpose of physical protection, it is necessary to differentiate between applications which can, if manipulated, directly endanger the protection goals. The importance of software protection is growing. In particular, because of ageing of components, the existing instrumentation and control systems with their fixed wiring and discrete elements will have to be updated. Computerized access control systems play an eminent role in the physical protection of a nuclear facility. Therefore, most systems are operated as islands. The paper shows that linking of certain systems with other computer systems is possible without inadmissible drawbacks for the physical protection level. It is shown by means of the example of linking together the computer networks of access control, health physics, the flexitime system, the key administration and the operational management system that such linking of systems in nuclear facilities had hidden advantages for all participants

  4. Characterization of accessibility for affine connection control systems at some points with nonzero velocity

    CERN Document Server

    Barbero-Liñán, María

    2011-01-01

    Affine connection control systems are mechanical control systems that model a wide range of real systems such as robotic legs, hovercrafts, planar rigid bodies, rolling pennies, snakeboards and so on. In 1997 the accessibility and a particular notion of controllability was intrinsically described by A. D. Lewis and R. Murray at points of zero velocity. Here, we present a novel generalization of the description of accessibility algebra for those systems at some points with nonzero velocity as long as the affine connection restricts to the distribution given by the symmetric closure. The results are used to describe the accessibility algebra of different mechanical control systems.

  5. Tracing and quantification of pharmaceuticals using MR imaging and spectroscopy at clinical MRI system

    Science.gov (United States)

    Jeong, Eun-Kee; Liu, Xin; Shi, Xianfeng; Yu, Y. Bruce; Lu, Zeng-Rong

    2012-10-01

    Magnetic resonance imaging (MRI) and spectroscopy (MRS) is very powerful modality for imaging and localized investigation of biological tissue. Medical MRI measures nuclear magnetization of the water protons, which consists of 70 % of our body. MRI provides superior contrast among different soft tissues to all other existing medical imaging modalities, including ultrasound, X-ray CT, PET, and SPECT. In principle, MRI/S may be an ideal non-invasive tool for drug delivery research. However, because of its low sensitivity, a large dose is required for tracing pharmaceuticals. Therefore, its use for imaging of pharmaceuticals is very limited mostly to molecules that contain a paramagnetic metal ion, such as gadolinium (Gd3+) and manganese (Mn2+). The paramagnetic metal ion provides a large fluctuating magnetic field at the proton in the water molecule via a coordinate site. The measurement of local drug concentration is the first step for further quantification. Local concentration of the paramagnetic-ion based MRI contrast agent can be indirectly measured via the change in the water signal intensity. 19F MRI/S of fluorinated complex may be an option for drug delivery and tracing agent, because the fluorinated molecule may be directly detected due to its large magnetic moment (94 % of proton) and 100 % abundance.

  6. Human engineering considerations in designing a computerized controlled access security system

    International Nuclear Information System (INIS)

    This paper describes a human engineering effort in the design of a major security system upgrade at Lawrence Livermore National Laboratory. This upgrade was to be accomplished by replacing obsolete and difficult-to-man (i.e., multiple operator task actions required) security equipment and systems with a new, automated, computer-based access control system. The initial task was to assist the electronic and mechanical engineering staff in designing a computerized security access system too functionally and ergonomically accommodate 100% of the Laboratory user population. The new computerized access system was intended to control entry into sensitive exclusion areas by requiring personnel to use an entry booth-based system and/or a remote access control panel system. The primary user interface with the system was through a control panel containing a magnetic card reader, function buttons, LCD display, and push-button keypad

  7. High-Speed Optical Local Access Network System Using Bi-Directional Polarization Multiplexing

    Institute of Scientific and Technical Information of China (English)

    Mitsuru Miyauchi; Yanjun Sun

    2003-01-01

    A high-speed and economical optical local access network system is proposed where bi-directional polarization multiplexing is applied to a bi-directional transmission. Experimental results using a prototype system confirmlow optical loss and environmental stabilities.

  8. High-Speed Optical Local Access Network System Using Bi-Directional Polarization Multiplexing

    Institute of Scientific and Technical Information of China (English)

    Mitsuru; Miyauchi; Yanjun; Sun

    2003-01-01

    A high-speed and economical optical local access network system is proposed where bi-directional polarization multiplexing is applied to a bi-directional transmission. Experimental results using a prototype system confirm low optical loss and environmental stabilities.

  9. Clinical evaluation of a computer-aided diagnosis system for determining cancer aggressiveness in prostate MRI

    International Nuclear Information System (INIS)

    To investigate the added value of computer-aided diagnosis (CAD) on the diagnostic accuracy of PIRADS reporting and the assessment of cancer aggressiveness. Multi-parametric MRI and histopathological outcome of MR-guided biopsies of a consecutive set of 130 patients were included. All cases were prospectively PIRADS reported and the reported lesions underwent CAD analysis. Logistic regression combined the CAD prediction and radiologist PIRADS score into a combination score. Receiver-operating characteristic (ROC) analysis and Spearman's correlation coefficient were used to assess the diagnostic accuracy and correlation to cancer grade. Evaluation was performed for discriminating benign lesions from cancer and for discriminating indolent from aggressive lesions. In total 141 lesions (107 patients) were included for final analysis. The area-under-the-ROC-curve of the combination score was higher than for the PIRADS score of the radiologist (benign vs. cancer, 0.88 vs. 0.81, p = 0.013 and indolent vs. aggressive, 0.88 vs. 0.78, p < 0.01). The combination score correlated significantly stronger with cancer grade (0.69, p = 0.0014) than the individual CAD system or radiologist (0.54 and 0.58). Combining CAD prediction and PIRADS into a combination score has the potential to improve diagnostic accuracy. Furthermore, such a combination score has a strong correlation with cancer grade. (orig.)

  10. Application of extracellular gadolinium-based MRI contrast agents and the risk of nephrogenic systemic fibrosis.

    Science.gov (United States)

    Heverhagen, J T; Krombach, G A; Gizewski, E

    2014-07-01

    Nephrogenic systemic fibrosis (NSF) is a serious, sometimes fatal disease. Findings in recent years have shown that a causal association between gadolinium containing contrast media and NSF is most likely. Therefore, the regulatory authorities have issued guidelines on the use of gadolinium-containing contrast media which have reduced the number of new cases of NSF to almost zero. However, it is for precisely this reason that the greatest care must still be taken to ensure that these guidelines are complied with. The most important factors are renal function, the quantity of gadolinium administered and coexisting diseases such as inflammation. All of these factors crucially influence the quantity of gadolinium released from the chelat in the body. This free gadolinium is thought to be the trigger for NSF. Other important factors are the stability of the gadolinium complex and furthermore the route of its elimination from the body. Partial elimination via the liver might be an additional protective mechanism. In conclusion, despite the NSF risk, contrast-enhanced MRI is a safe diagnostic procedure which can be used reliably and safely even in patients with severe renal failure, and does not necessarily have to be replaced by other methods.

  11. Clinical evaluation of a computer-aided diagnosis system for determining cancer aggressiveness in prostate MRI

    Energy Technology Data Exchange (ETDEWEB)

    Litjens, Geert J.S.; Barentsz, Jelle O.; Karssemeijer, Nico; Huisman, Henkjan J. [Radboud University Medical Center, Department of Radiology, Nijmegen (Netherlands)

    2015-11-15

    To investigate the added value of computer-aided diagnosis (CAD) on the diagnostic accuracy of PIRADS reporting and the assessment of cancer aggressiveness. Multi-parametric MRI and histopathological outcome of MR-guided biopsies of a consecutive set of 130 patients were included. All cases were prospectively PIRADS reported and the reported lesions underwent CAD analysis. Logistic regression combined the CAD prediction and radiologist PIRADS score into a combination score. Receiver-operating characteristic (ROC) analysis and Spearman's correlation coefficient were used to assess the diagnostic accuracy and correlation to cancer grade. Evaluation was performed for discriminating benign lesions from cancer and for discriminating indolent from aggressive lesions. In total 141 lesions (107 patients) were included for final analysis. The area-under-the-ROC-curve of the combination score was higher than for the PIRADS score of the radiologist (benign vs. cancer, 0.88 vs. 0.81, p = 0.013 and indolent vs. aggressive, 0.88 vs. 0.78, p < 0.01). The combination score correlated significantly stronger with cancer grade (0.69, p = 0.0014) than the individual CAD system or radiologist (0.54 and 0.58). Combining CAD prediction and PIRADS into a combination score has the potential to improve diagnostic accuracy. Furthermore, such a combination score has a strong correlation with cancer grade. (orig.)

  12. Applying the Earth System Grid Security System in a Heterogeneous Environment of Data Access Services

    Science.gov (United States)

    Kershaw, Philip; Lawrence, Bryan; Lowe, Dominic; Norton, Peter; Pascoe, Stephen

    2010-05-01

    CEDA (Centre for Environmental Data Archival) based at STFC Rutherford Appleton Laboratory is host to the BADC (British Atmospheric Data Centre) and NEODC (NERC Earth Observation Data Centre) with data holdings of over half a Petabyte. In the coming months this figure is set to increase by over one Petabyte through the BADC's role as one of three data centres to host the CMIP5 (Coupled Model Intercomparison Project Phase 5) core archive of climate model data. Quite apart from the problem of managing the storage of such large volumes there is the challenge of collating the data together from the modelling centres around the world and enabling access to these data for the user community. An infrastructure to support this is being developed under the US Earth System Grid (ESG) and related projects bringing together participating organisations together in a federation. The ESG architecture defines Gateways, the web interfaces that enable users to access data and data serving applications organised into Data Nodes. The BADC has been working in collaboration with US Earth System Grid team and other partners to develop a security system to restrict access to data. This provides single sign-on via both OpenID and PKI based means and uses role based authorisation facilitated by SAML and OpenID based interfaces for attribute retrieval. This presentation will provide an overview of the access control architecture and look at how this has been implemented for CEDA. CEDA has developed an expertise in data access and information services over several years through a number of projects to develop and enhance these capabilities. Participation in CMIP5 comes at a time when a number of other software development activities are coming to fruition. New services are in the process of being deployed alongside services making up the system for ESG. The security system must apply access control across this heterogeneous environment of different data services and technologies. One strand

  13. H1DS: A new web-based data access system

    International Nuclear Information System (INIS)

    Highlights: • We present H1DS, a new RESTful web service for accessing fusion data. • We examine the scalability and extensibility of H1DS. • We present a fast and user friendly web browser client for the H1DS web service. • A summary relational database is presented as an application of the H1DS API. - Abstract: A new data access system, H1DS, has been developed and deployed for the H-1 Heliac at the Australian Plasma Fusion Research Facility. The data system provides access to fusion data via a RESTful web service. With the URL acting as the API to the data system, H1DS provides a scalable and extensible framework which is intuitive to new users, and allows access from any internet connected device. The H1DS framework, originally designed to work with MDSplus, has a modular design which can be extended to provide access to alternative data storage systems

  14. Improving Potable Water Accessibility And Sustainability Through Efficient Management Of Pipe Water Supply System

    OpenAIRE

    Nakabugo, Stella Mirembe

    2015-01-01

    This paper discusses how to improve potable water accessibility and sustainability through efficient management of pipe water supply system a case study of Uganda, Kampala region. Kampala the capital city of Uganda still faces a challenge to access clean potable water. Water supply coverage is 77.5 % showing at least 22.5 % of the total population has limited access to potable drinking water causing a gap between water supply and water demand. Hypotheses of the paper were that the city's popu...

  15. Providing access to a Public Transport Schedule system for Smart Phone Clients

    OpenAIRE

    Hameseder, Katrin

    2010-01-01

    This master thesis was conducted during an internship at HBT GmbH with the purpose of providing access to an existing public transport schedule system in Hamburg (Germany) for smart phone clients. A state-of-the-art literature review and an evaluation of an existing SOAP (Simple Object Access Protocol) based web service to access public transport schedule information were conducted to identify the drawbacks of the existing interface with respect to the limitations and characteristics of smart...

  16. On board processing for future satellite communications systems: Comparison of FDM, TDM and hybrid accessing schemes

    Science.gov (United States)

    Berk, G.; Jean, P. N.; Rotholz, E.

    1982-01-01

    Several satellite uplink and downlink accessing schemes for customer premises service are compared. Four conceptual system designs are presented: satellite-routed frequency division multiple access (FDMA), satellite-switched time division multiple access (TDMA), processor-routed TDMA, and frequency-routed TDMA, operating in the 30/20 GHz band. The designs are compared on the basis of estimated satellite weight, system capacity, power consumption, and cost. The systems are analyzed for fixed multibeam coverage of the continental United States. Analysis shows that the system capacity is limited by the available satellite resources and by the terminal size and cost.

  17. Whole-body MRI: comprehensive evaluation on a 48-channel 3T MRI system in less than 40 minutes. Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Hernandes, Mateus de Andrade; Semelka, Richard C.; Bamrungchart, Saraporn; Stallings, Clifton, E-mail: richsem@med.unc.edu [Department of Radiology, University of North Carolina, Chapel Hill, NC (United States); Elias Junior, Jorge [Imaging and Medical Physics Center, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP (Brazil); Dale, Brian M. [Siemens Medical Solutions USA, Inc., Cary, NC (United States)

    2012-11-15

    Objective: To evaluate a comprehensive MRI protocol that investigates for cancer, vascular disease, and degenerative/inflammatory disease from the head to the pelvis in less than 40 minutes on a new generation 48-channel 3T system. Materials and Methods: All MR studies were performed on a 48-channel 3T MR scanner. A 20-channel head/neck coil, two 18-channel body arrays, and a 32-channel spine array were employed. A total of 4 healthy individuals were studied. The designed protocol included a combination of single-shot T2-weighted sequences, T1-weighted 3D gradient echo pre- and post-gadolinium. All images were retrospectively evaluated by two radiologists independently for overall image quality. Results: The image quality for cancer was rated as excellent in the liver, pancreas, kidneys, lungs, pelvic organs, and brain, and rated as fair in the colon and breast. For vascular diseases ratings were excellent in the aorta, major branch vessel origins, inferior vena cava, portal and hepatic veins, rated as good in pulmonary arteries, and as poor in the coronary arteries. For degenerative/inflammatory diseases ratings were excellent in the brain, liver and pancreas. The inter-observer agreement was excellent. Conclusion: A comprehensive and time efficient screening for important categories of disease processes may be achieved with high quality imaging in a new generation 48-channel 3T system. (author)

  18. Whole-body MRI: comprehensive evaluation on a 48-channel 3T MRI system in less than 40 minutes. Preliminary results

    Directory of Open Access Journals (Sweden)

    Mateus de Andrade Hernandes

    2012-12-01

    Full Text Available OBJECTIVE: To evaluate a comprehensive MRI protocol that investigates for cancer, vascular disease, and degenerative/inflammatory disease from the head to the pelvis in less than 40 minutes on a new generation 48-channel 3T system. MATERIALS AND METHODS: All MR studies were performed on a 48-channel 3T MR scanner. A 20-channel head/neck coil, two 18-channel body arrays, and a 32-channel spine array were employed. A total of 4 healthy individuals were studied. The designed protocol included a combination of single-shot T2-weighted sequences, T1-weighted 3D gradient-echo pre- and post-gadolinium. All images were retrospectively evaluated by two radiologists independently for overall image quality. RESULTS: The image quality for cancer was rated as excellent in the liver, pancreas, kidneys, lungs, pelvic organs, and brain, and rated as fair in the colon and breast. For vascular diseases ratings were excellent in the aorta, major branch vessel origins, inferior vena cava, portal and hepatic veins, rated as good in pulmonary arteries, and as poor in the coronary arteries. For degenerative/inflammatory diseases ratings were excellent in the brain, liver and pancreas. The inter-observer agreement was excellent. CONCLUSION: A comprehensive and time efficient screening for important categories of disease processes may be achieved with high quality imaging in a new generation 48-channel 3T system.

  19. Evaluation of malformations of the fetal central nervous system using fetal MRI; Das fetale MRT in der praenatalen Beurteilung von ZNS-Stoerungen

    Energy Technology Data Exchange (ETDEWEB)

    Blondin, D. [Inst. fuer Diagnostische Radiologie, Universitaetsklinikum Duesseldorf (Germany); Schaper, J.; Klee, D.; Moedder, U. [Inst. fuer Diagnostische Radiologie, Kinderradiologie, Universitaetsklinikum Duesseldorf (Germany); Reihs, T. [Frauenklinik, Universitaetsklinikum Duesseldorf (Germany); Hammer, R. [Gemeinschaftspraxis, Praenatal-Medizin und Genetik, Duesseldorf (Germany); Messing-Juenger, M. [Abt. Neurochirurgie, Klinik Sankt Augustin (Germany)

    2008-08-15

    Purpose: ultrasound as the primary prenatal screening modality is used to detect fetal anomalies. Aim of the study was to prove the additional value of fetal magnetic resonance imaging (MRI). Materials and methods: in 25 pregnant women (age 30.6 {+-} 4.8; 24 single and one twin pregnancy) with pathologic findings of the central nervous system detected by obstetric ultrasound, a fetal MRI was performed. All sequences (T2w-HASTE, TRUEFISP, T1w-FLASH 2D, DWI) were performed using the breath-hold technique. The results were compared to postnatal MRI or ultrasound scan findings and tested for correlation with the clinical course and development of these children. Results: three to seven days after ultrasound, an MRI of all 26 fetuses without sedation was performed (26.6 {+-} 4.0 GW). One healthy twin was not included in this study. MRI confirmed the ultrasonographic diagnosis in 7 cases. Compared to ultrasound, an additional pathology could be detected by MRI in 8 cases. In 10 cases ultrasound diagnosis was overruled by MRI. Prenatal MRI findings were confirmed by postnatal imaging in 18 children. The clinical course was predictable in 8 of 15 cases, depending on the pathology detected. Three newborns died in the perinatal period. (orig.)

  20. ACCESS TO A COMPUTER SYSTEM. BETWEEN LEGAL PROVISIONS AND TECHNICAL REALITY

    Directory of Open Access Journals (Sweden)

    Maxim DOBRINOIU

    2016-05-01

    Full Text Available Nowadays, on a rise of cybersecurity incidents and a very complex IT&C environment, the national legal systems must adapt in order to properly address the new and modern forms of criminality in cyberspace. The illegal access to a computer system remains one of the most important cyber-related crimes due to its popularity but also from the perspective as being a door opened to computer data and sometimes a vehicle for other tech crimes. In the same time, the information society services slightly changed the IT paradigm and represent the new interface between users and systems. Is true that services rely on computer systems, but accessing services goes now beyond the simple accessing computer systems as commonly understood by most of the legislations. The article intends to explain other sides of the access related to computer systems and services, with the purpose to advance possible legal solutions to certain case scenarios.

  1. MRI assessment of lumbar intervertebral disc degeneration with lumbar degenerative disease using the Pfirrmann grading systems.

    Directory of Open Access Journals (Sweden)

    Li-Peng Yu

    Full Text Available BACKGROUND: To evaluate by MRI intervertebral disc degeneration in patients with lumbar degenerative disease using the Pfirrmann grading system and to determine whether Modic changes correlated with the Pfirrmann grades and modified Pfirrmann grades of disc degeneration. METHODS: The clinical data of 108 surgical patients with lumbar degenerative disease were reviewed and their preoperative MR images were analyzed. Disc degeneration was evaluated using the Pfirrmann grading system. Patients were followed up and low back pain was evaluated using the visual analog scale (VAS and the effect of back pain on the daily quality of life was assessed using Oswestry disability index (ODI. RESULTS: Forty-four cases had normal anatomical appearance (Modic type 0 and their Pfirrmann grades were 3.77±0.480 and their modified Pfirrmann grades were of 5.81±1.006. Twenty-seven cases had Modic type I changes and their Pfirrmann grades were 4.79±0.557 and their modified Pfirrmann grades were 7.00±0.832. Thirty-six cases exhibited Modic type II changes and their Pfirrmann grades and modified Pfirrmann grades were 4.11±0.398 and 6.64±0.867, respectively. One case had Modic type III changes. Kruskal-Wallis test revealed significant difference in modified Pfirrmann grade among Modic type 0, I and II changes (P0.05. Binary regression analysis showed that Modic changes correlated most strongly with disc degeneration. Follow up studies indicated that the VAS and ODI scores were markedly improved postoperatively. However, no difference was noted in VAS and ODI scores among patients with different Modic types. CONCLUSION: Modic changes correlate with the Pfirrmann and modified Pfirrmann grades of disc degeneration in lumbar degenerative disease. There is no significant correlation between Modic types and surgical outcomes.

  2. Improving vascular access outcomes: a systems approach to eliminating structural barriers.

    Science.gov (United States)

    Sands, Jeffrey J; Perry, Michael A

    2003-01-01

    Maximizing AV fistula creation, regular access monitoring, prompt outpatient interventions and minimizing catheter use are well-accepted approaches for vascular access management. Systemic barriers impede the application of these strategies. A misaligned reimbursement system coupled with educational deficits and a lack of accountability has contributed to the institutionalization of substandard vascular access care. The hallmark of performance management is to create systems in which incentives are aligned to produce desired behaviors. Realigning reimbursement through a combination of pre-ESRD funding, enhancements to the composite rate to reward outcomes and cover vascular access monitoring and updated reimbursement for outpatient vascular access procedures would improve care and decrease unnecessary hospitalizations. This should be coupled with clearly defined outcome standards and accountability incorporated into hospital accreditation and credentialing. Capitation may provide alternative solutions. A two-phased approach including reimbursement reform while exploring capitation represents a prudent course with the best likelihood of success. PMID:12596756

  3. Effect of insulating layer material on RF-induced heating for external fixation system in 1.5 T MRI system.

    Science.gov (United States)

    Liu, Yan; Kainz, Wolfgang; Qian, Songsong; Wu, Wen; Chen, Ji

    2014-09-01

    The radio frequency (RF)-induced heating is a major concern when patients with medical devices are placed inside a magnetic resonance imaging (MRI) system. In this article, numerical studies are applied to investigate the potentials of using insulated materials to reduce the RF heating for external fixation devices. It is found that by changing the dielectric constant of the insulation material, the RF-induced heating at the tips of devices can be altered. This study indicates a potential technique of developing external fixation device with low MRI RF heating.

  4. Evaluation on the Occupational Information Access System as Used at Churchill High School. A Project Report.

    Science.gov (United States)

    McKinlay, Bruce; Adams, Daniel

    The Occupational Information Access System (OIAS) improves the accessibility of occupational labor market information for career planning. Its operation at Churchill High School is evaluated from several angels: the likes and dislikes of users; the effect of OIAS on users' knowledge of occupational information and on their career plans; why other…

  5. Visual Cortex Plasticity Following Peripheral Damage To The Visual System: fMRI Evidence.

    Science.gov (United States)

    Lemos, João; Pereira, Daniela; Castelo-Branco, Miguel

    2016-10-01

    Over the last two decades, functional magnetic resonance imaging (fMRI) has become a powerful research method to investigate cortical visual plasticity. Abnormal fMRI response patterns have been occasionally detected in the visually deprived cortex of patients with bilateral retinal diseases. Controversy remains whether these observations indicate structural reorganization of the visual cortex or unmasking of previously silent cortico-cortical connections. In optic nerve diseases, there is weak evidence showing that early visual cortex seems to lack reorganization, while higher-order visual areas undergo plastic changes which may contribute to optimise visual function. There is however accumulating imaging evidence demonstrating trans-synaptic degeneration of the visual cortex in patients with disease of the anterior visual pathways. This may preclude the use of restorative treatments in these patients. Here, we review and update the body of fMRI evidence on visual cortical plasticity. PMID:27542799

  6. Breast dosimetry in transverse and longitudinal field MRI-Linac radiotherapy systems

    International Nuclear Information System (INIS)

    Purpose: In the framework of developing the integration of a MRI-Linac system, configurations of MRI-Linac units were simulated in order to improve the dose distribution in tangential breast radiotherapy using transverse and longitudinal magnetic field geometries of Lorentz force for both medial and lateral tangential fields. Methods: In this work, the GEANT4 Monte Carlo (MC) code was utilized to compare dose distributions in breast radiotherapy for Linac-MR systems in the transverse and longitudinal geometries within humanoid phantoms across a range of magnetic field strengths of 0.5 and 1.5 T. The dose increment due to scattering from the coils was investigated for both geometries as well. Computed tomography images of two patients were used for MC simulations. One patient had intact breast while the other was mastectomized. In the simulations, planning and methods of chest wall irradiation were similar to the actual clinical planning. Results: In a longitudinal geometry, the magnetic field is shown to restrict the lateral spread of secondary electrons to the lung, heart, and contralateral organs, which reduced the mean dose of the ipsilateral lung and heart by means of 17.2% and 6% at 1.5 T, respectively. The transverse configuration exhibits a significant increase in tissue interface effects, which increased dose buildup in the entrance regions of the lateral and medial tangent beams to the planning target volume (PTV) and improved dose homogeneity within the PTV. The improved relative average homogeneity index for two patients to the PTV at magnetic field strength of 1.5 T with respect to no magnetic field case evaluated was 11.79% and 34.45% in the LRBP and TRBP geometries, respectively. In both geometries, the simulations show significant mean dose reductions in the contralateral breast and chest wall skin, respectively, by a mean of 16.6% and 24.9% at 0.5 T and 17.2% and 28.1% at 1.5 T in the transverse geometry, and 10.56% and 14.6% at 0.5 T and 11.3% and

  7. Coupled circuit numerical analysis of eddy currents in an open MRI system.

    Science.gov (United States)

    Akram, Md Shahadat Hossain; Terada, Yasuhiko; Keiichiro, Ishi; Kose, Katsumi

    2014-08-01

    We performed a new coupled circuit numerical simulation of eddy currents in an open compact magnetic resonance imaging (MRI) system. Following the coupled circuit approach, the conducting structures were divided into subdomains along the length (or width) and the thickness, and by implementing coupled circuit concepts we have simulated transient responses of eddy currents for subdomains in different locations. We implemented the Eigen matrix technique to solve the network of coupled differential equations to speed up our simulation program. On the other hand, to compute the coupling relations between the biplanar gradient coil and any other conducting structure, we implemented the solid angle form of Ampere's law. We have also calculated the solid angle for three dimensions to compute inductive couplings in any subdomain of the conducting structures. Details of the temporal and spatial distribution of the eddy currents were then implemented in the secondary magnetic field calculation by the Biot-Savart law. In a desktop computer (Programming platform: Wolfram Mathematica 8.0®, Processor: Intel(R) Core(TM)2 Duo E7500 @ 2.93GHz; OS: Windows 7 Professional; Memory (RAM): 4.00GB), it took less than 3min to simulate the entire calculation of eddy currents and fields, and approximately 6min for X-gradient coil. The results are given in the time-space domain for both the direct and the cross-terms of the eddy current magnetic fields generated by the Z-gradient coil. We have also conducted free induction decay (FID) experiments of eddy fields using a nuclear magnetic resonance (NMR) probe to verify our simulation results. The simulation results were found to be in good agreement with the experimental results. In this study we have also conducted simulations for transient and spatial responses of secondary magnetic field induced by X-gradient coil. Our approach is fast and has much less computational complexity than the conventional electromagnetic numerical simulation

  8. Coupled circuit numerical analysis of eddy currents in an open MRI system.

    Science.gov (United States)

    Akram, Md Shahadat Hossain; Terada, Yasuhiko; Keiichiro, Ishi; Kose, Katsumi

    2014-08-01

    We performed a new coupled circuit numerical simulation of eddy currents in an open compact magnetic resonance imaging (MRI) system. Following the coupled circuit approach, the conducting structures were divided into subdomains along the length (or width) and the thickness, and by implementing coupled circuit concepts we have simulated transient responses of eddy currents for subdomains in different locations. We implemented the Eigen matrix technique to solve the network of coupled differential equations to speed up our simulation program. On the other hand, to compute the coupling relations between the biplanar gradient coil and any other conducting structure, we implemented the solid angle form of Ampere's law. We have also calculated the solid angle for three dimensions to compute inductive couplings in any subdomain of the conducting structures. Details of the temporal and spatial distribution of the eddy currents were then implemented in the secondary magnetic field calculation by the Biot-Savart law. In a desktop computer (Programming platform: Wolfram Mathematica 8.0®, Processor: Intel(R) Core(TM)2 Duo E7500 @ 2.93GHz; OS: Windows 7 Professional; Memory (RAM): 4.00GB), it took less than 3min to simulate the entire calculation of eddy currents and fields, and approximately 6min for X-gradient coil. The results are given in the time-space domain for both the direct and the cross-terms of the eddy current magnetic fields generated by the Z-gradient coil. We have also conducted free induction decay (FID) experiments of eddy fields using a nuclear magnetic resonance (NMR) probe to verify our simulation results. The simulation results were found to be in good agreement with the experimental results. In this study we have also conducted simulations for transient and spatial responses of secondary magnetic field induced by X-gradient coil. Our approach is fast and has much less computational complexity than the conventional electromagnetic numerical simulation

  9. Identifying brain systems for gaze orienting during reading: fMRI investigation of the Landolt paradigm

    Directory of Open Access Journals (Sweden)

    Rebekka eHillen

    2013-07-01

    Full Text Available The Landolt reading paradigm was created in order to dissociate effects of eye movements and attention from lexical, syntactic, and sub-lexical processing. While previous eye-tracking and behavioural findings support the usefulness of the paradigm, it remains to be shown that the paradigm actually relies on the brain networks for occulomotor control and attention, but not on systems for lexical/syntactic/orthographic processing. Here, 20 healthy volunteers underwent fMRI scanning while reading sentences (with syntax or unconnected lists of written stimuli (no syntax consisting of words (with semantics or pseudowords (no semantics. In an additional "Landolt reading" condition, all letters were replaced by closed circles, which should be scanned for targets (Landolt's rings in a reading-like fashion from left to right. A conjunction analysis of all five conditions revealed the visual scanning network which involved bilateral visual cortex, premotor cortex, and superior parietal cortex, but which did not include regions for semantics, syntax, or orthography. Contrasting the Landolt reading condition with all other regions revealed additional involvement of the right superior parietal cortex (areas 7A/7P/7PC and postcentral gyrus (area 2 involved in deliberate gaze shifting. These neuroimaging findings demonstrate for the first time that the linguistic and orthographic brain network can be dissociated from a pure gaze-orienting network with the Landolt paradigm. Consequently, the Landolt paradigm may provide novel insights into the contributions of linguistic and non-linguistic factors on reading failure e.g. in developmental dyslexia.

  10. Coupled circuit numerical analysis of eddy currents in an open MRI system

    Science.gov (United States)

    Akram, Md. Shahadat Hossain; Terada, Yasuhiko; Keiichiro, Ishi; Kose, Katsumi

    2014-08-01

    We performed a new coupled circuit numerical simulation of eddy currents in an open compact magnetic resonance imaging (MRI) system. Following the coupled circuit approach, the conducting structures were divided into subdomains along the length (or width) and the thickness, and by implementing coupled circuit concepts we have simulated transient responses of eddy currents for subdomains in different locations. We implemented the Eigen matrix technique to solve the network of coupled differential equations to speed up our simulation program. On the other hand, to compute the coupling relations between the biplanar gradient coil and any other conducting structure, we implemented the solid angle form of Ampere’s law. We have also calculated the solid angle for three dimensions to compute inductive couplings in any subdomain of the conducting structures. Details of the temporal and spatial distribution of the eddy currents were then implemented in the secondary magnetic field calculation by the Biot-Savart law. In a desktop computer (Programming platform: Wolfram Mathematica 8.0®, Processor: Intel(R) Core(TM)2 Duo E7500 @ 2.93 GHz; OS: Windows 7 Professional; Memory (RAM): 4.00 GB), it took less than 3 min to simulate the entire calculation of eddy currents and fields, and approximately 6 min for X-gradient coil. The results are given in the time-space domain for both the direct and the cross-terms of the eddy current magnetic fields generated by the Z-gradient coil. We have also conducted free induction decay (FID) experiments of eddy fields using a nuclear magnetic resonance (NMR) probe to verify our simulation results. The simulation results were found to be in good agreement with the experimental results. In this study we have also conducted simulations for transient and spatial responses of secondary magnetic field induced by X-gradient coil. Our approach is fast and has much less computational complexity than the conventional electromagnetic numerical

  11. A computer-aided detection system for rheumatoid arthritis MRI data interpretation and quantification of synovial activity

    Energy Technology Data Exchange (ETDEWEB)

    Kubassova, Olga, E-mail: olga@imageanalysis.org.u [Image Analysis Ltd., The Waterfront, Old Mill Lane, Saltaire BD17 7EZ (United Kingdom); Boesen, Mikael, E-mail: parker@frh.regionh.d [Parker Institute, Frederiksberg Hospital, Nordre Fasanvej 57, 2000 Frederiksberg, Copenhagen (Denmark); Cimmino, Marco A., E-mail: cimmino@unige.i [Clinica Reumatologica, DI.M.I., Universita di Genova, Viale Benedetto XV, 6, 16129 Genova (Italy); Bliddal, Henning [Parker Institute, Frederiksberg Hospital, Nordre Fasanvej 57, 2000 Frederiksberg, Copenhagen (Denmark)

    2010-06-15

    Rational and objective: Disease assessment and follow-up of rheumatoid arthritis (RA) patients require objective evaluation and quantification. Magnetic resonance imaging (MRI) has a large potential to supplement such information for the clinician, however, time spent on data reading and interpretation slow down development in this area. Existing scoring systems of especially synovitis are too rigid and insensitive to measure early treatment response and quantify inflammation. This study tested a novel automated, computer system for analysis of dynamic MRI data acquired from patients with RA, Dynamika-RA, which incorporates efficient data processing and analysis techniques. Materials and methods: 140 MRI scans from hands and wrists of 135 active RA patients and 5 healthy controls were processed using Dynamika-RA and evaluated with RAMRIS. To reduce patient motion artefacts, MRI data were processed using Dynamika-RA, which removed motion in 2D and 3D planes. Then synovial enhancement was visualised and qualified using a novel fully automated voxel-by-voxel analysis based algorithm. This algorithm was used to replace traditional region-of-interest (ROI) and subtraction methods, yielding observer independent quantitative results. Results: Conventional scoring performed by an observer took 30-45 min per dataset. Dynamika-RA reduced motion artefacts, visualised inflammation and quantified disease activity in less than 3 min. Data processing allowed increasing signal to noise ratio by a factor 3. Due to fully automated procedure of data processing, there was no intertest variation in the results. Conclusions: Algorithms incorporated into Dynamika-RA allow for the significant enhancement of data quality through eliminating motion artefacts and reduction of time for evaluation of synovial inflammation.

  12. A Fault-Tolerant Emergency-Aware Access Control Scheme for Cyber-Physical Systems

    CERN Document Server

    Wu, Guowei; Xia, Feng; Yao, Lin

    2012-01-01

    Access control is an issue of paramount importance in cyber-physical systems (CPS). In this paper, an access control scheme, namely FEAC, is presented for CPS. FEAC can not only provide the ability to control access to data in normal situations, but also adaptively assign emergency-role and permissions to specific subjects and inform subjects without explicit access requests to handle emergency situations in a proactive manner. In FEAC, emergency-group and emergency-dependency are introduced. Emergencies are processed in sequence within the group and in parallel among groups. A priority and dependency model called PD-AGM is used to select optimal response-action execution path aiming to eliminate all emergencies that occurred within the system. Fault-tolerant access control polices are used to address failure in emergency management. A case study of the hospital medical care application shows the effectiveness of FEAC.

  13. Effects of Job Accessibility Improved by Public Transport System: Natural Experimental Evidence from the Copenhagen Metro

    DEFF Research Database (Denmark)

    Pons Rotger, Gabriel Angel; Nielsen, Thomas Alexander Sick

    2015-01-01

    This study examines the effect of accessibility to urban jobs via a public transport system on individual earnings and commuting behaviour. The effect of improved public transport based accessibility on these outcomes is determined by exploiting the exogenous variation in access to a public rail...... and Metro system resulting from the construction of a new terminal Metro station connecting southern townships to Copenhagen city centre. The results show that public transport based job accessibility has a positive and permanent effect on individual earnings. The increase in earnings is associated...... with a change in commuting patterns as the improved access to public transport facilitates a shift from employment within the township to better paid jobs in the city centre, as well as in other suburbs of the Copenhagen Metropolitan area...

  14. A Unified Approach to Optimal Opportunistic Spectrum Access under Collision Probability Constraint in Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2010-01-01

    Full Text Available We consider a cognitive radio system with one primary channel and one secondary user, and then we introduce a channel-usage pattern model and a fundamental access scheme in this system. Based on this model and fundamental access scheme, we study optimal opportunistic spectrum access problem and formulate it as an optimization problem that the secondary user maximizes spectrum holes utilization under the constraint of collision tolerable level. And then we propose a unified approach to solve this optimization problem. According to the solution of the optimization problem, we analyze and present optimal opportunistic spectrum access algorithms in several cases that the idle period follows uniform distribution, exponential distribution, and Pareto or generalized Pareto distribution. Theoretical analysis and simulation results both show that the optimal opportunistic spectrum access algorithms can maximize spectrum holes utilization under the constraint that the collision probability is bounded below collision tolerable level. The impact of sensing error is also analyzed by simulation.

  15. 75 FR 4101 - Enterprise Income Verification (EIV) System User Access Authorization Form and Rules of Behavior...

    Science.gov (United States)

    2010-01-26

    ... of Behavior and User Agreement AGENCY: Office of the Chief Information Officer, HUD. ACTION: Notice... (EIV) System User Access, Authorization Form and Rules Of Behavior and User Agreement. OMB...

  16. Intraoperative MRI in pediatric brain tumors

    International Nuclear Information System (INIS)

    Intraoperative magnetic resonance imaging (iMRI) has emerged as an important tool in guiding the surgical management of children with brain tumors. Recent advances have allowed utilization of high field strength systems, including 3-tesla MRI, resulting in diagnostic-quality scans that can be performed while the child is on the operating table. By providing information about the possible presence of residual tumor, it allows the neurosurgeon to both identify and resect any remaining tumor that is thought to be safely accessible. By fusing the newly obtained images with the surgical guidance software, the images have the added value of aiding in navigation to any residual tumor. This is important because parenchyma often shifts during surgery. It also gives the neurosurgeon insight into whether any immediate postoperative complications have occurred. If any complications have occurred, the child is already in the operating room and precious minutes lost in transport and communications are saved. In this article we review the three main approaches to an iMRI system design. We discuss the possible roles for iMRI during intraoperative planning and provide guidance to help radiologists and neurosurgeons alike in the collaborative management of these children. (orig.)

  17. Intraoperative MRI in pediatric brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Choudhri, Asim F. [Le Bonheur Children' s Hospital, Department of Radiology, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Neurosurgery, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Ophthalmology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Siddiqui, Adeel [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Klimo, Paul; Boop, Frederick A. [University of Tennessee Health Science Center, Department of Neurosurgery, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Semmes-Murphey Neurologic and Spine Institute, Memphis, TN (United States); St. Jude Children' s Hospital, Division of Neurosurgery, Department of Surgery, Memphis, TN (United States)

    2015-09-15

    Intraoperative magnetic resonance imaging (iMRI) has emerged as an important tool in guiding the surgical management of children with brain tumors. Recent advances have allowed utilization of high field strength systems, including 3-tesla MRI, resulting in diagnostic-quality scans that can be performed while the child is on the operating table. By providing information about the possible presence of residual tumor, it allows the neurosurgeon to both identify and resect any remaining tumor that is thought to be safely accessible. By fusing the newly obtained images with the surgical guidance software, the images have the added value of aiding in navigation to any residual tumor. This is important because parenchyma often shifts during surgery. It also gives the neurosurgeon insight into whether any immediate postoperative complications have occurred. If any complications have occurred, the child is already in the operating room and precious minutes lost in transport and communications are saved. In this article we review the three main approaches to an iMRI system design. We discuss the possible roles for iMRI during intraoperative planning and provide guidance to help radiologists and neurosurgeons alike in the collaborative management of these children. (orig.)

  18. Quantitative Clinical Evaluation of a Simultaneous PETI MRI Breast Imaging System

    Energy Technology Data Exchange (ETDEWEB)

    Schlyer D. J.; Schlyer, D.J.

    2013-04-03

    A prototype simultaneous PET-MRI breast scanner has been developed for conducting clinical studies with the goal of obtaining high resolution anatomical and functional information in the same scan which can lead to faster and better diagnosis, reduction of unwanted biopsies, and better patient care.

  19. A Fine-Grained Data Access Control System in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Boniface K. Alese

    2015-12-01

    Full Text Available The evolving realities of Wireless Sensor Network (WSN deployed to various terrain of life require serving multiple applications. As large amount of sensed data are distributed and stored in individual sensors nodes, the illegal access to these sensitive data can be devastating. Consequently, data insecurity becomes a big concern. This study, therefore, proposes a fine-grained access control system which only requires the right set of users to access a particular data, based on their access privileges in the sensor networks. It is designed using Priccess Protocol with Access policy formulation adopting the principle of Bell Lapadula model as well as Attribute-Based Encryption (ABE to control access to sensor data. The functionality of the proposed system is simulated using Netbeans. The performance analysis of the proposed system using execution time and size of the key show that the higher the key size, the harder it becomes for the attacker to hack the system. Additionally, the time taken for the proposed work is lesser which makes the work faster than the existing work. Consequently, a well secure interactive web-based application that could facilitates the field officers access to stored data in safe and secure manner is developed.

  20. Key issues of multiple access technique for LEO satellite communication systems

    Institute of Scientific and Technical Information of China (English)

    温萍萍; 顾学迈

    2004-01-01

    The large carrier frequency shift caused by the high-speed movement of satellite (Doppler effects) and the propagation delay on the up-down link are very critical issues in an LEO satellite communication system, which affects both the selection and the implementation of a suitable access method. A Doppler based multiple access technique is used here to control the flow and an MPRMA-HS protocol is proposed for the application in LEO satellite communication systems. The extended simulation trials prove that the proposed scheme seems to be a very promising access method.

  1. Asynchronous Free-Space Optical CDMA Communications System for Last-mile Access Network

    DEFF Research Database (Denmark)

    Jurado-Navas, Antonio; Raddo, Thiago R.; Sanches, Anderson L.;

    2016-01-01

    We propose a new hybrid asynchronous OCDMA-FSO communications system for access network solutions. New ABER expressions are derived under gamma-gamma scintillation channels, where all users can surprisingly achieve error-free transmissions when FEC is employed.......We propose a new hybrid asynchronous OCDMA-FSO communications system for access network solutions. New ABER expressions are derived under gamma-gamma scintillation channels, where all users can surprisingly achieve error-free transmissions when FEC is employed....

  2. The new biometric access control system resembles a big electronic eye. It will be used to control access to the LHC from 2007 onwards.

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The new LHC access control systems will soon be using the latest technology: optical recognition based on iris image data. In order to gain access to the tunnel it will be your eye, not your credentials that you'll be required to show! As of September, the entrance point at Point 8 should be the first to be fitted out with iris recognition equipment. The other access shafts will then gradually be equipped one by one.

  3. Bluetooth Navigation System using Wi-Fi Access Points

    OpenAIRE

    Rohit Agrawal; Ashesh Vasalya

    2012-01-01

    There have been various navigation and tracking systems being developed with the help of technologies like GPS, GSM, Bluetooth, IR, Wi-Fi and Radar. Outdoor positioning systems have been deployed quite successfully using GPS but positioning systems for indoor environments still do not have widespread deployment due to various reasons. Most of these use only a single technology for positioning but using more than one in cooperation with each other is always advantageous for obtaining greater ...

  4. Computer-assisted three-dimensional reconstruction of the corticospinal system as a reference for CT and MRI

    International Nuclear Information System (INIS)

    We present a three-dimensional (3D) anatomical computer-graphics model of the corticospinal system acquired from equidistant serial anatomical slices of six intracranially-fixed human brains. This model is part of a neuroanatomical reference system (NeuRef) which enables 3D visualization of the brain and shows the relationship of its components such as anatomical structures, functional fibre tracts and arteries. Sections through the models can be matched with corresponding CT or MR images. This allows the probable localisation of corticospinal fibres on CT or MRI. (orig.) (orig.)

  5. Comparative Evaluation of Diagnostic Value of Prenatal USG and MRI in the Diagnosis of Fetal Central Nervous System Defects

    OpenAIRE

    I. Herman-Sucharska; M. Bekiesińska-Figatowska; Andrzej Urbanik; A. Mamak-Balaga; A. Grzyb

    2011-01-01

    Background/Objective: The purpose of the study was"nto compare the diagnostic values of prenatal ultrasound"nand MRI in fetal central nervous system defects."nPatients and Methods: Three-hundred eighty-five"nMRIs were performed in pregnant women with the"nultrasound suspicion of fetal defect. US was conducted"nwith the Voluson-Kretz730PRO. In 158 cases (41%)"nfetal CNS defect was found. MR was performed with the"n1.5T system, torso surface coil, SSFSET2...

  6. Evaluation of the incidence of nephrogenic systemic fibrosis in patients with moderate renal insufficiency administered gadobenate dimeglumine for MRI

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, B.J. [Department of Radiology, Loma Linda University Medical Center, Loma Linda, California (United States)], E-mail: BJBryant@ahs.llumc.edu; Im, K.; Broome, D.R. [Department of Radiology, Loma Linda University Medical Center, Loma Linda, California (United States)

    2009-07-15

    Aim: To determine the incidence of nephrogenic systemic fibrosis (NSF) in stage 3 chronic kidney disease patients following intravenous exposure to gadobenate dimeglumine. Materials and methods: A prospective study was performed on 168 consecutive patients at a single institution with stage 3 chronic kidney disease who underwent clinically-indicated contrast-enhanced magnetic resonance imaging (MRI) examinations with gadobenate dimeglumine from January 2007 to March 2008. All patients were contacted by phone by investigators 3 months after MRI to verify the presence or absence of NSF signs or symptoms. If signs or symptoms suggestive of NSF developed, dermatologic referral was made and confirmatory skin biopsy performed if indicated. Results: One hundred and eighty contrast-enhanced MRI examinations with gadobenate dimeglumine were performed on the 168 patients. Twenty patients were lost to follow-up, but 160 incidents of contrast medium exposure were followed up for 3-months and 105 incidents were followed up for 6 months. The mean contrast medium dose per weight was 0.093 mmol/kg (range 0.042-0.153 mmol/kg). The mean estimated creatinine clearance was 50.4 ml/min/1.73 m{sup 2} (range from 30-59 ml/min/1.73 m{sup 2}). Ten patients developed skin rashes during the 3-month follow-up period, but none were confirmed to represent NSF (0% prevalence rate). No other signs or symptoms of NSF were reported. Conclusion: Based on this limited study, NSF does not appear to occur in patients with stage 3 chronic kidney disease exposed to intravenous gadobenate dimeglumine for MRI at standard dosing of {approx}0.1 mmol/kg.

  7. "Show me a justice system that's open, transparent, accessible and inclusive" : barriers to access in the criminal justice system for people with disabilities as victims of crime

    OpenAIRE

    Edwards, Claire; Harold, Gill; Kilcommins, Shane

    2015-01-01

    peer-reviewed This paper considers the barriers that people with disabilities in Ireland face in accessing justice through the criminal justice system when they are victims of crime. It draws on qualitative research with key actors working within the agencies of the Irish criminal justice system, along with disability organisations, victim support organisations and health and social care providers. The research identifies a number of barriers which can be differentiated in terms of those o...

  8. Towards a Reference Model for Open Access and Knowledge Sharing, Lessons from Systems Research

    Directory of Open Access Journals (Sweden)

    Paola Di Maio

    2011-09-01

    Full Text Available The Open Access Movement has been striving to grant universal unrestricted access to the knowledge and data outputs of publicly funded research. leveraging the real time, virtually cost free publishing opportunities offered by the internet and the web. However, evidence suggests that in the systems engineering domain open access policies are largely ignored. This paper presents the rationale, methodology and results of an evidence based inquiry that investigates the dichotomy between policy and practice in Open Access (OA of systems engineering research in the UK, explores entangled dimensions of the problem space from a socio-technical perspective, and issues a set of recommendations, including a reference model outline for knowledge sharing in systems research.

  9. Towards a Reference Model for Open Access and Knowledge Sharing, Lessons from Systems Research

    CERN Document Server

    Di Maio, Paola

    2011-01-01

    The Open Access Movement has been striving to grant universal unrestricted access to the knowledge and data outputs of publicly funded research. leveraging the real time, virtually cost free publishing opportunities offered by the internet and the web. However, evidence suggests that in the systems engineering domain open access policies are not widely adopted. This paper presents the rationale, methodology and results of an evidence based inquiry that investigates the dichotomy between policy and practice in Open Access (OA) of systems engineering research in the UK, explores entangled dimensions of the problem space from a socio-technical perspective, and issues a set of recommendations, including a reference model outline for knowledge sharing in systems research

  10. Co-Registration of MEG and ULF MRI using a 7 channel low-Tc SQUID system

    Energy Technology Data Exchange (ETDEWEB)

    Magnelind, Per E [Los Alamos National Laboratory; Sandin, Jan H [Los Alamos National Laboratory; Volegov, Petr L [Los Alamos National Laboratory; Matlashov, Andrei N [Los Alamos National Laboratory; Owens, Tuba [Los Alamos National Laboratory; Gomez, John J [Los Alamos National Laboratory; Espy, Michelle A [Los Alamos National Laboratory

    2010-01-01

    In human brain imaging, e.g. pre-surgical mapping, it is highly desired to obtain images with high spatial and temporal resolution. However, no single imaging device is capable of producing both a high spatial resolution anatomical image and a high temporal resolution functional image. During the last couple of years significant efforts have been directed towards magnetic resonance imaging (MRI) in fields comparable to the Earth's field, i.e. microtesla fields, or lower fields. The fields in this range are called ultra-low fields (ULF). Interestingly, the idea of magnetic resonance at microtesla fields is more than 50 years old. In ULF MR it is essential to use pre-polarization to increase the signal-to-noise ratio of the signal from the precessing spins, since the magnetization from the measurement field alone is very small. Even with the present level of prepolarization the ULF images are not as highly resolved as their high-field counterparts. By using a 7 channel system equipped with low transition temperature (T{sub c}) Superconducting QUantum Interference Devices (SQUIDs) to perform both ULF MRI and magnetoencephalography (MEG), it is possible to coregister a lower resolution ULF MR image and an MEG image obtained during one run. Thereby, the MEG data is aligned to the ULF MR image after performing a calibration run with a phantom. The ULF MR image can then be used to align the MEG data onto a high-field MR image. Recently, our group presented the first brain images obtained by ULF MRI. The MR imaging was combined with an MEG session performed a posteriori. The subject's head was moved in between the MRI run and the MEG run and no reference coils were used to quantify the translation. The main reason for the translation of the head was to improve the coverage of the auditory evoked response. In this paper, we report interleaved ULF MRI and MEG measurements co-registered in the same system.

  11. Measuring the Gap Between Car and Transit Accessibility : Estimating Access Using a High-Resolution Transit Network Geographic Information System

    NARCIS (Netherlands)

    Benenson, I.; Martens, C.J.C.M.; Rofé, Y.

    2010-01-01

    Accessibility is increasingly identified in the academic literature and in planning practice as a key criterion to assess transport policies and urban land use development. This paper contributes in two respects to the growing body of literature on accessibility and accessibility measurement. First,

  12. CDC STATE System E-Cigarette Legislation - Youth Access

    Data.gov (United States)

    U.S. Department of Health & Human Services — 1995-2016. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. E-Cigarette Legislation—Youth...

  13. A Secure Infrastructure For System Console and Reset Access

    CERN Document Server

    Horváth, A; Schulz, M; Horvath, Andras; Leonardi, Emanuele; Schulz, Markus

    2003-01-01

    During the last years large farms have been built using commodity hardware. This hardware lacks components for remote and automated administration. Products that can be retrofitted to these systems are either costly or inherently insecure. We present a system based on serial ports and simple machine controlled relays. We report on experience gained by setting up a 50-machine test environment as well as current work in progress in the area.

  14. Signal restoration in intensity-modulated optical OFDM access systems.

    Science.gov (United States)

    Vanin, Evgeny

    2011-11-15

    It is well known that deliberate signal clipping in an intensity-modulated (IM) laser transmitter helps to overcome the optical orthogonal frequency division multiplexing (OFDM) system performance limitation that is related to the signal high peak-to-average power ratio. The amplitude of a clipped OFDM signal has to be optimized in order to minimize the optical power that is required to achieve a specified system performance. However, the signal clipping introduces nonlinear distortion (so-called clipping noise) and leads to a system performance penalty. In this Letter, the performance of the IM optical OFDM system with digital baseband clipping distortion in the transmitter and clipping noise compensation by means of signal restoration in the digital signal processing unit of the system receiver is analytically evaluated. It is demonstrated that the system bit-error ratio can be reduced by more than an order of magnitude, from 10(-3) to 3.5×10(-5), by applying only the first iteration of the signal restoration algorithm proposed in this Letter. The results of the analytical analysis are verified with brute-force numerical simulations based on direct error counting. PMID:22089556

  15. Fetal Brain MRI

    Directory of Open Access Journals (Sweden)

    Ahmad Tahmasebpour

    2010-05-01

    Full Text Available MRI is a useful supplement to ultrasonography for the assessment of fetal brain malformations. Superior soft tissue contrast and the ability to depict sulcation and myelination are the strengths of MRI. Subtle or inconclusive ultrasonography abnormalities can be confirmed or ruled out by MRI. In some cases, additional findings detected with MRI often help in arriving at a definitive diagnosis, which is necessary for parental counseling and for guiding management. Fast T2W sequences form the basis of fetal MRI. There have been no reports of deleterious effects of MRI on the fetus. A few case examples are presented to illustrate the advantages of MRI. "nThe database comprises MR images of a total of 26 fetuses (gestational age 22-23 weeks reformed be-cause of suspected abnormalities due to ultrasonic findings, family history or maternal illness and scanned on a 1.5T MR system using single-shot fast spin echo "SSFSE, HASTE" T2 sequence, slice thick-ness 3mm, no gap. "HASTE=fourier acquisition single shotturbospinecho". In the normal fetus the ventricular size or volume did not vary with the gestational age but cerebral and cerebellar volumes increase during the same period "Grossman et al." Diagnostic accuracy is about 48%. "OB/GYN news, Chicago". Today it is not necessary to use sedatives or muscle relaxants to control fetal movement "ultra-fast MRI techniques". Modified technique for 50% reduction in the time necessary to take MRI images of the fetal brain is dedicated by Kianosh Hosseinzadeh, by using a line of reference through the eyes "AJR 2005"."nOur fetuses are 22-23 weeks in gestational age, 26 in number and we found agenesis of corpus callosum, hydrocephaly, holoprosencephaly, mega-cisterna magna, occipital meningocele, Arnold Chiari malformation type 1, Dandy Walker syndrome and lissencephaly

  16. 5 CFR 293.504 - Composition of, and access to, the Employee Medical File System.

    Science.gov (United States)

    2010-01-01

    ... Employee Medical File System. 293.504 Section 293.504 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Employee Medical File System Records § 293.504 Composition of, and access to, the Employee Medical File System. (a) All employee occupational medical...

  17. Central nervous system infectious diseases mimicking multiple sclerosis: recognizing distinguishable features using MRI

    Directory of Open Access Journals (Sweden)

    Antonio Jose da Rocha

    2013-09-01

    Full Text Available The current diagnostic criteria for multiple sclerosis (MS confirm the relevant role of magnetic resonance imaging (MRI, supporting the possibility of characterizing the dissemination in space (DIS and the dissemination in time (DIT in a single scan. To maintain the specificity of these criteria, it is necessary to determine whether T2/FLAIR visible lesions and the gadolinium enhancement can be attributed to diseases that mimic MS. Several diseases are included in the MS differential diagnosis list, including diseases with exacerbation, remitting periods and numerous treatable infectious diseases, which can mimic the MRI features of MS. We discuss the most relevant imaging features in several infectious diseases that resemble MS and examine the primary spatial distributions of lesions and the gadolinium enhancement patterns related to MS. Recognizing imaging "red flags" can be useful for the proper diagnostic evaluation of suspected cases of MS, facilitating the correct differential diagnosis by assessing the combined clinical, laboratory and MR imaging information.

  18. 28 CFR 25.6 - Accessing records in the system.

    Science.gov (United States)

    2010-07-01

    ... law enforcement and other relevant record systems, and may provide a unique State-Assigned Transaction... “Denied” response. (h) POC Determination Messages. POCs shall transmit electronic NICS transaction... FFL. For transactions where a determination has not been communicated to the FFL, the...

  19. Access Control for Monitoring System-Spanning Business Processes

    NARCIS (Netherlands)

    Bassil, S.; Reichert, M.U.; Bobrik, R.; Bauer, Th.

    2007-01-01

    Integrated process support is highly desirable in environ- ments where data related to a particular (business) process are scattered over distributed and heterogeneous information systems (IS). A process monitoring component is a much-needed module in order to provide an integrated view on all these

  20. Cognitive Spectrum Efficient Multiple Access Technique using Relay Systems

    DEFF Research Database (Denmark)

    Frederiksen, Flemming Bjerge; Prasad, Ramjee

    2007-01-01

    Methods to enhance the use of the frequency spectrum by automatical spectrum sensing plus spectrum sharing in a cognitive radio technology context will be presented and discussed in this paper. Ideas to increase the coverage of cellular systems by relay channels, relay stations and collaborate...... radio will be presented as well....

  1. Labeling and Rating Systems: Greater Access or Censorship?

    Science.gov (United States)

    Martin, Ann M.

    2015-01-01

    This article asks the question: How well versed are school librarians on issues related to labeling and rating systems? As school librarians continue to design and implement resource location schemes to assist patrons, they must recognize the difference between using labels to create interest in books or implementing labeling and rating systems…

  2. Neural systems for social cognition in Klinefelter syndrome (47,XXY): evidence from fMRI

    OpenAIRE

    van Rijn, Sophie; Swaab, Hanna; Baas, Daan; de Haan, Edward; Kahn, René S; Aleman, André

    2011-01-01

    Klinefelter syndrome (KS) is a chromosomal condition (47, XXY) that may help us to unravel gene–brain behavior pathways to psychopathology. The phenotype includes social cognitive impairments and increased risk for autism traits. We used functional MRI to study neural mechanisms underlying social information processing. Eighteen nonclinical controls and thirteen men with XXY were scanned during judgments of faces with regard to trustworthiness and age. While judging faces as untrustworthy in ...

  3. Dissecting the human medial temporal lobe memory system by functional MRI

    OpenAIRE

    Weis, Christine Susanne

    2004-01-01

    The work presented in this thesis comprises two event-related functional magnetic resonance imaging (fMRI) studies, which aim at dissociating the contributions of different subregions of the human medial temporal lobe (MTL) to declarative memory processes. The first study examines common neural correlates of memory encoding and recognition. Healthy subjects were scanned both while they memorized photographs of buildings and landscapes and while they tried to recognize these pictures in a seri...

  4. SU-E-J-205: Dose Distribution Differences Caused by System Related Geometric Distortion in MRI-Guided Radiation Treatment System

    International Nuclear Information System (INIS)

    Purpose: MRI has superb soft tissue contrast but is also known for geometric distortions. The concerns and uncertainty about MRI’s geometric distortion have contributed to the hesitation of using only MRI for simulation in radiation therapy. There are two major categories of geometric distortion in MRI; system related and patient related. In this presentation, we studied the impact of system-related geometric distortion on dose distribution in a digital body phantom under an MR-Linac environment. Methods: Residual geometric distortion (after built-in geometric correction) was modeled based on phantom measurements of the system-related geometric distortions of a MRI scanner of a combined MR guided Radiation Therapy (MRgRT) system. A digital oval shaped phantom (40×25 cm) as well as one ellipsoid shaped tumor volume was created to simulate a simplified human body. The simulated tumor volume was positioned at several locations between the isocenter and the body surface. CT numbers in HUs that approximate soft tissue and tumor were assigned to the respective regions in the digital phantom. To study the effect of geometric distortion caused by system imperfections, an IMRT plan was optimized with the distorted image set with the B field. Dose distributions were re-calculated on the undistorted image set with the B field (as in MR-Linac). Results: The maximum discrepancies in both body contour and tumor boundary was less than 2 mm, which leads to small dose distribution change. For the target in the center, coverage was reduced from 98.8% (with distortion) to 98.2%; for the other peripheral target coverage was reduced from 98.4% to 95.9%. Conclusion: System related geometric distortions over the 40×25 area were within 2mm and the resulted dosimetric effects were minor for the two tumor locations in the phantom. Patient study will be needed for further investigation. The authors received a corporate research grant from Elekta

  5. SU-E-J-205: Dose Distribution Differences Caused by System Related Geometric Distortion in MRI-Guided Radiation Treatment System

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J; Yang, J; Wen, Z [MD Anderson Cancer Center, Houston, TX (United States); Marshall, S [Monaco, Elekta AB, Tampa, FL (Monaco); Court, L; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: MRI has superb soft tissue contrast but is also known for geometric distortions. The concerns and uncertainty about MRI’s geometric distortion have contributed to the hesitation of using only MRI for simulation in radiation therapy. There are two major categories of geometric distortion in MRI; system related and patient related. In this presentation, we studied the impact of system-related geometric distortion on dose distribution in a digital body phantom under an MR-Linac environment. Methods: Residual geometric distortion (after built-in geometric correction) was modeled based on phantom measurements of the system-related geometric distortions of a MRI scanner of a combined MR guided Radiation Therapy (MRgRT) system. A digital oval shaped phantom (40×25 cm) as well as one ellipsoid shaped tumor volume was created to simulate a simplified human body. The simulated tumor volume was positioned at several locations between the isocenter and the body surface. CT numbers in HUs that approximate soft tissue and tumor were assigned to the respective regions in the digital phantom. To study the effect of geometric distortion caused by system imperfections, an IMRT plan was optimized with the distorted image set with the B field. Dose distributions were re-calculated on the undistorted image set with the B field (as in MR-Linac). Results: The maximum discrepancies in both body contour and tumor boundary was less than 2 mm, which leads to small dose distribution change. For the target in the center, coverage was reduced from 98.8% (with distortion) to 98.2%; for the other peripheral target coverage was reduced from 98.4% to 95.9%. Conclusion: System related geometric distortions over the 40×25 area were within 2mm and the resulted dosimetric effects were minor for the two tumor locations in the phantom. Patient study will be needed for further investigation. The authors received a corporate research grant from Elekta.

  6. Massive M2M Access with Reliability Guarantees in LTE Systems

    DEFF Research Database (Denmark)

    Madueño, Germán Corrales; Kiilerich Pratas, Nuno; Stefanovic, Cedomir;

    2015-01-01

    Machine-to-Machine (M2M) communications are one of the major drivers of the cellular network evolution towards 5G systems. One of the key challenges is on how to provide reliability guarantees to each accessing device in a situation in which there is a massive number of almost-simultaneous arrivals...... approach, based on a standard operation of the cellular access. The access procedure is divided into two phases, an estimation phase and a serving phase. In the estimation phase the number of arrivals is estimated and this information is used to tune the amount of resources allocated in the serving phase...

  7. Generation-based memory synchronization in a multiprocessor system with weakly consistent memory accesses

    Science.gov (United States)

    Ohmacht, Martin

    2014-09-09

    In a multiprocessor system, a central memory synchronization module coordinates memory synchronization requests responsive to memory access requests in flight, a generation counter, and a reclaim pointer. The central module communicates via point-to-point communication. The module includes a global OR reduce tree for each memory access requesting device, for detecting memory access requests in flight. An interface unit is implemented associated with each processor requesting synchronization. The interface unit includes multiple generation completion detectors. The generation count and reclaim pointer do not pass one another.

  8. Real-Time Image Reconstruction and Display System for MRI Using a High-Speed Personal Computer

    Science.gov (United States)

    Haishi, Tomoyuki; Kose, Katsumi

    1998-09-01

    A real-time NMR image reconstruction and display system was developed using a high-speed personal computer and optimized for the 32-bit multitasking Microsoft Windows 95 operating system. The system was operated at various CPU clock frequencies by changing the motherboard clock frequency and the processor/bus frequency ratio. When the Pentium CPU was used at the 200 MHz clock frequency, the reconstruction time for one 128 × 128 pixel image was 48 ms and that for the image display on the enlarged 256 × 256 pixel window was about 8 ms. NMR imaging experiments were performed with three fast imaging sequences (FLASH, multishot EPI, and one-shot EPI) to demonstrate the ability of the real-time system. It was concluded that in most cases, high-speed PC would be the best choice for the image reconstruction and display system for real-time MRI.

  9. Scheduling with Bus Access Optimization for Distributed Embedded Systems

    DEFF Research Database (Denmark)

    Eles, Petru; Doboli, Alex; Pop, Paul;

    2000-01-01

    In this paper, we concentrate on aspects related to the synthesis of distributed embedded systems consisting of programmable processors and application-specific hardware components. The approach is based on an abstract graph representation that captures, at process level, both dataflow and the flow...... of control. Our goal is to derive a worst case delay by which the system completes execution, such that this delay is as small as possible; to generate a logically and temporally deterministic schedule; and to optimize parameters of the communication protocol such that this delay is guaranteed. We have...... have to be considered during scheduling but also the parameters of the communication protocol should be adapted to fit the particular embedded application. The optimization algorithm, which implies both process scheduling and optimization of the parameters related to the communication protocol...

  10. Does the sound of a barking dog activate its corresponding visual form? An fMRI investigation of modality-specific semantic access.

    Science.gov (United States)

    Reilly, Jamie; Garcia, Amanda; Binney, Richard J

    2016-08-01

    Much remains to be learned about the neural architecture underlying word meaning. Fully distributed models of semantic memory predict that the sound of a barking dog will conjointly engage a network of distributed sensorimotor spokes. An alternative framework holds that modality-specific features additionally converge within transmodal hubs. Participants underwent functional MRI while covertly naming familiar objects versus newly learned novel objects from only one of their constituent semantic features (visual form, characteristic sound, or point-light motion representation). Relative to the novel object baseline, familiar concepts elicited greater activation within association regions specific to the presentation modality. Furthermore, visual form elicited activation within high-level auditory association cortex. Conversely, environmental sounds elicited activation in regions proximal to visual association cortex. Both conditions commonly engaged a putative hub region within lateral anterior temporal cortex. These results support hybrid semantic models in which local hubs and distributed spokes are dually engaged in service of semantic memory. PMID:27289210

  11. Multi-tag content access control in RFID system

    OpenAIRE

    Xue, Shun

    2010-01-01

    Radio Frequency Identification (RFID) makes great flexibility and high efficiency for data acquisition in industry and daily life. At the other side, it brings the privacy risks and multiple tags collision issue. Current research in RFID system focuses on the security and privacy issue which is based on authentication protocols between a tag and a Reader. There is a need to design a reasonable protocol which takes care of both multi-tag anti-collision and security issue. This thesis presen...

  12. Geoculture world system, access to Balkan and Albania

    Directory of Open Access Journals (Sweden)

    Ilirjan Çukaj

    2015-03-01

    Full Text Available If culture as a term covers a broad range of relations and social behavior, mutually implicated in influential and economic cycles of the global system, then it becomes wordy geoculture. Geoculture system is used as a term by Wallerstein (2004 who had treated it as a concept largely unused and under a theory of geoculture which plays an important role in the present world system. The theses that is presented in this article is that the global trajectory in the Balkan region is increasing from culture and that, it is imperative to establish a strategic culture direction and management, which, in turn, should be formed not only as a principal need, but also as an obligation of social state institutions to find the viable solutions of the global market policy, economy and culture. And in response to the challenging question the culture of integration becomes imperative now facing nationalism. Albania will have to manage perceptions, fears and realities arising from the above mentioned phenomenon, to establish a balance between the “inside” and “outside” views. In this sense main challenge of Albania is the management of cultural globalization to get the most of opportunities despite the risk of losing ground globally

  13. Using geographic information system tools to improve access to MS specialty care in Veterans Health Administration

    OpenAIRE

    William J. Culpepper, II, PhD, MA; Diane Cowper-Ripley, PhD; Eric R. Litt, BA; Tzu-Yun McDowell, MA; Paul M. Hoffman, MD

    2010-01-01

    Access to appropriate and timely healthcare is critical to the overall health and well-being of patients with chronic diseases. In this study, we used geographic information system (GIS) tools to map Veterans Health Administration (VHA) patients with multiple sclerosis (MS) and their access to MS specialty care. We created six travel-time bands around VHA facilities with MS specialty care and calculated the number of VHA patients with MS who resided in each time band and the number of patient...

  14. Security Guidelines for the Development of Accessible Web Applications through the implementation of intelligent systems

    Directory of Open Access Journals (Sweden)

    Luis Joyanes Aguilar

    2009-12-01

    Full Text Available Due to the significant increase in threats, attacks and vulnerabilities that affect the Web in recent years has resulted the development and implementation of pools and methods to ensure security measures in the privacy, confidentiality and data integrity of users and businesses. Under certain circumstances, despite the implementation of these tools do not always get the flow of information which is passed in a secure manner. Many of these security tools and methods cannot be accessed by people who have disabilities or assistive technologies which enable people to access the Web efficiently. Among these security tools that are not accessible are the virtual keyboard, the CAPTCHA and other technologies that help to some extent to ensure safety on the Internet and are used in certain measures to combat malicious code and attacks that have been increased in recent times on the Web. Through the implementation of intelligent systems can detect, recover and receive information on the characteristics and properties of the different tools and hardware devices or software with which the user is accessing a web application and through analysis and interpretation of these intelligent systems can infer and automatically adjust the characteristics necessary to have these tools to be accessible by anyone regardless of disability or navigation context. This paper defines a set of guidelines and specific features that should have the security tools and methods to ensure the Web accessibility through the implementation of intelligent systems.

  15. Masked assessment of MRI findings: is it possible to differentiate neuro-Behcet`s disease from other central nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Coban, O.; Bahar, S.; Akman-Demir, G.; Tasci, B.; Serdaroglu, P. [Univ. of Istanbul (Turkey). Dept. of Neurology; Yurdakul, S.; Yazici, H. [Univ. of Istanbul (Turkey). Dept. of Internal Medicine

    1999-04-01

    Two neuroradiologists reviewed MRI studies of 34 patients with neuro-Behcet`s disease (NBD), 22 with multiple sclerosis (MS) and 7 with systemic lupus erythematosus (SLE) with central nervous system involvement, masked to the clinical diagnosis, age and sex of the patients. Of the patients with NBD 12 were in an acute attack; the others had chronic disease. MRI was assessed using a set of criteria, looking at atrophy, the site of discrete parenchymal lesions, regions of predominant involvement and the extent of the lesion(s). The observers also made a guess at the clinical diagnosis. The brain stem and/or basal ganglia were the most predominantly involved sites in all patients with acute NBD; 75 % of these lesions were large and confluent, mainly extending from the brain stem to the diencephalon and basal ganglia. However, in chronic cases, the predominant involvement was in the brain stem and/or basal ganglia in only 36 %, and in cerebral hemisphere white matter in another 36 %; 27 % of these patients showed no parenchymal lesion. Hemisphere white-matter lesions were equally distributed between periventricular and other areas in NBD, while in MS more were periventricular, and in SLE more were nonperiventricular. Brain-stem atrophy was seen in 21 % of patients with NBD, with a specificity of 96.5 %. In the absence of cortical atrophy, its specificity was 100 %. The attempt at making a radiological diagnosis was successful in all cases of acute NBD and 95.5 % of patients with MS, but in only 40 % of patients with chronic NBD. Most of this latter groups MRI studies were interpreted as MS. An extensive lesion involving the brain stem and basal ganglia seemed to be diagnostic of acute NBD. However, hemisphere white-matter lesions could not be differentiated from those in MS. (orig.) With 3 figs., 6 tabs., 18 refs.

  16. Systems requirements for cable modems in high-speed access networks

    Science.gov (United States)

    Campos, Luis A.; Su, Shing-Fong

    1996-11-01

    Cable modems play an important role in turning the hybrid fiber coax (HFC) networks from pure broadcast video service to high-speed access networks. Many CATV companies and telephone companies are experimenting with high-speed data services over HFC. With today's technology, cable modems can easily run at a data rate of 10 Mbps or above. They allow subscribers fast access to on-line services and the Internet. A variety of cable modems have been developed and marketed by cable modem vendors. Selection of right cable modems for deployment in HFC access networks has become a nontrivial matter. Different HFC systems may require different types of cable modems. In this paper, we review the development of HFC systems and discuss data networking using approaches that include connectionless data networking and connection-oriented data networking systems. The system requirements for cable modems in terms of throughput, robustness, ease of operation, protocol efficiency, reliability, network management, and cost are addressed.

  17. Cognitive radio networks medium access control for coexistence of wireless systems

    CERN Document Server

    Bian, Kaigui; Gao, Bo

    2014-01-01

    This book gives a comprehensive overview of the medium access control (MAC) principles in cognitive radio networks, with a specific focus on how such MAC principles enable different wireless systems to coexist in the same spectrum band and carry out spectrum sharing.  From algorithm design to the latest developments in the standards and spectrum policy, readers will benefit from leading-edge knowledge of how cognitive radio systems coexist and share spectrum resources.  Coverage includes cognitive radio rendezvous, spectrum sharing, channel allocation, coexistence in TV white space, and coexistence of heterogeneous wireless systems.   • Provides a comprehensive reference on medium access control (MAC)-related problems in the design of cognitive radio systems and networks; • Includes detailed analysis of various coexistence problems related to medium access control in cognitive radio networks; • Reveals novel techniques for addressing the challenges of coexistence protocol design at a higher level ...

  18. Rules and access rights of the Estonian integrated e-Health system.

    Science.gov (United States)

    Tiik, Madis

    2010-01-01

    There should be a clear understanding that when implementing an electronic health record system (EHR), one of the hardest problems we have to solve is the access rights. In Estonia this process lasted for three years and involved all stakeholders of the healthcare sector. Special ethical committee was established to advise the decision makers and doctors to help them understand the ethical dilemmas from the patient's and society's point of view. In this article you will find a short overview of the access rights of the system, roles of the healthcare systems' employees. Descriptions of some specific situations like underage patients and representation of patient with restricted active legal capacity.

  19. An Information System to Access Status Information of the LHCb Online

    International Nuclear Information System (INIS)

    The LHCb collaboration consists of roughly 700 physicists from 52 institutes and universities. Most of the collaborating physicists - including subdetector experts - are not permanently based at CERN. This paper describes the architecture used to publish data internal to the LHCb experiment control- and data acquisition system to the World Wide Web. Collaborators can access the online (sub-) system status and the system performance directly from the institute abroad, from home or from a smart phone without the need of direct access to the online computing infrastructure.

  20. Access to essential medicines in Pakistan: policy and health systems research concerns.

    Directory of Open Access Journals (Sweden)

    Shehla Zaidi

    Full Text Available INTRODUCTION: Inadequate access to essential medicines is a common issue within developing countries. Policy response is constrained, amongst other factors, by a dearth of in-depth country level evidence. We share here i gaps related to access to essential medicine in Pakistan; and ii prioritization of emerging policy and research concerns. METHODS: An exploratory research was carried out using a health systems perspective and applying the WHO Framework for Equitable Access to Essential Medicine. Methods involved key informant interviews with policy makers, providers, industry, NGOs, experts and development partners, review of published and grey literature, and consultative prioritization in stakeholder's Roundtable. FINDINGS: A synthesis of evidence found major gaps in essential medicine access in Pakistan driven by weaknesses in the health care system as well as weak pharmaceutical regulation. 7 major policy concerns and 11 emerging research concerns were identified through consultative Roundtable. These related to weaknesses in medicine registration and quality assurance systems, unclear and counterproductive pricing policies, irrational prescribing and sub-optimal drug availability. Available research, both locally and globally, fails to target most of the identified policy concerns, tending to concentrate on irrational prescriptions. It overlooks trans-disciplinary areas of policy effectiveness surveillance, consumer behavior, operational pilots and pricing interventions review. CONCLUSION: Experience from Pakistan shows that policy concerns related to essential medicine access need integrated responses across various components of the health systems, are poorly addressed by existing evidence, and require an expanded health systems research agenda.

  1. A Distributed Metadata Management, Data Discovery and Access System

    CERN Document Server

    Palanisamy, Giriprakash; Green, Jim; Wilson, Bruce

    2010-01-01

    Mercury is a federated metadata harvesting, search and retrieval tool based on both open source and software developed at Oak Ridge National Laboratory. It was originally developed for NASA, and the Mercury development consortium now includes funding from NASA, USGS, and DOE. A major new version of Mercury was developed during 2007. This new version provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, support for RSS delivery of search results, among other features. Mercury provides a single portal to information contained in disparate data management systems. It collects metadata and key data from contributing project servers distributed around the world and builds a centralized index. The Mercury search interfaces then allow the users to perform simple, fielded, spatial and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fa...

  2. Pediatric MRI

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIH Study of Normal Brain Development is a longitudinal study using anatomical MRI, diffusion tensor imaging (DTI), and MR spectroscopy (MRS) to map pediatric...

  3. Functional requirements with survey results for integrated intrusion detection and access control annunciator systems

    Energy Technology Data Exchange (ETDEWEB)

    Arakaki, L.H.; Monaco, F.M.

    1995-09-01

    This report contains the guidance Functional Requirements for an Integrated Intrusion Detection and Access Control Annunciator System, and survey results of selected commercial systems. The survey questions were based upon the functional requirements; therefore, the results reflect which and sometimes how the guidance recommendations were met.

  4. 28 CFR 16.73 - Exemption of Office of Legal Policy System-limited access.

    Science.gov (United States)

    2010-07-01

    ... Office of Legal Policy System—limited access. (a) The following system of records is exempt from 5 U.S.C..., or legal obligations or duties. (4) From subsections (e)(4)(G) and (H) because this system is exempt... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of Office of Legal...

  5. Experimental grid access for dynamic discovery and data transfer in distributed interactive simulation systems

    NARCIS (Netherlands)

    A. Tirado-Ramos; K. Zajac; Z. Zhao; P.M.A. Sloot; G.D. van Albada; M. Bubak

    2003-01-01

    Interactive Problem Solving Environments (PSEs) offer an integrated approach for constructing and running complex systems, such as distributed simulation systems. New distributed infrastructures, like the Grid, support the access to a large variety of core services and resources that can be used by

  6. Multi-level access control in the data pipeline of the international supply chain system

    NARCIS (Netherlands)

    Pruksasri, P.; Berg, J. van den; Hofman, W.; Daskapan, S.

    2013-01-01

    The Seamless Integrated Data Pipeline system was proposed to the European Union in order to overcome the information quality shortcomings of the current international supply chain information exchange systems. Next to identification and authorization of stakeholders, secure access control needs to b

  7. Environmental Information Management For Data Discovery and Access System

    Science.gov (United States)

    Giriprakash, P.

    2011-01-01

    Mercury is a federated metadata harvesting, search and retrieval tool based on both open source software and software developed at Oak Ridge National Laboratory. It was originally developed for NASA, and the Mercury development consortium now includes funding from NASA, USGS, and DOE. A major new version of Mercury was developed during 2007 and released in early 2008. This new version provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, support for RSS delivery of search results, and ready customization to meet the needs of the multiple projects which use Mercury. For the end users, Mercury provides a single portal to very quickly search for data and information contained in disparate data management systems. It collects metadata and key data from contributing project servers distributed around the world and builds a centralized index. The Mercury search interfaces then allow ! the users to perform simple, fielded, spatial and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data.

  8. SU-E-J-210: Characterizing Tissue Equivalent Materials for the Development of a Dual MRI-CT Heterogeneous Anthropomorphic Phantom Designed Specifically for MRI Guided Radiotherapy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Steinmann, A; Stafford, R; Yung, J; Followill, D [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: MRI guided radiotherapy (MRIgRT) is an emerging technology which will eventually require a proficient quality auditing system. Due to different principles in which MR and CT acquire images, there is a need for a multi-imaging-modality, end-to-end QA phantom for MRIgRT. The purpose of this study is to identify lung, soft tissue, and tumor equivalent substitutes that share similar human-like CT and MR properties (i.e. Hounsfield units and relaxation times). Methods: Materials of interested such as common CT QA phantom materials, and other proprietary gels/silicones from Polytek, SmoothOn, and CompositeOne were first scanned on a GE 1.5T Signa HDxT MR. Materials that could be seen on both T1-weighted and T2-weighted images were then scanned on a GE Lightspeed RT16 CT simulator and a GE Discovery 750HD CT scanner and their HU values were then measured. The materials with matching HU values of lung (−500 to −700HU), muscle (+40HU) and soft tissue (+100 to +300HU) were further scanned on GE 1.5T Signa HDx to measure their T1 and T2 relaxation times from varying parameters of TI and TE. Results: Materials that could be visualized on T1-weighted and T2-weighted images from a 1.5T MR unit and had an appropriate average CT number, −650, −685, 46,169, and 168 HUs were: compressed cork saturated with water, Polytek Platsil™ Gel-00 combined with mini styrofoam balls, radiotherapy bolus material, SmoothOn Dragon-Skin™ and SmoothOn Ecoflex™, respectively. Conclusion: Post processing analysis is currently being performed to accurately map T1 and T2 values for each material tested. From previous MR visualization and CT examinations it is expected that Dragon-Skin™, Ecoflex™ and bolus will have values consistent with tissue and tumor substitutes. We also expect compressed cork statured with water, and Polytek™-styrofoam combination to have approximate T1 and T2 values suitable for lung-equivalent materials.

  9. SU-E-J-210: Characterizing Tissue Equivalent Materials for the Development of a Dual MRI-CT Heterogeneous Anthropomorphic Phantom Designed Specifically for MRI Guided Radiotherapy Systems

    International Nuclear Information System (INIS)

    Purpose: MRI guided radiotherapy (MRIgRT) is an emerging technology which will eventually require a proficient quality auditing system. Due to different principles in which MR and CT acquire images, there is a need for a multi-imaging-modality, end-to-end QA phantom for MRIgRT. The purpose of this study is to identify lung, soft tissue, and tumor equivalent substitutes that share similar human-like CT and MR properties (i.e. Hounsfield units and relaxation times). Methods: Materials of interested such as common CT QA phantom materials, and other proprietary gels/silicones from Polytek, SmoothOn, and CompositeOne were first scanned on a GE 1.5T Signa HDxT MR. Materials that could be seen on both T1-weighted and T2-weighted images were then scanned on a GE Lightspeed RT16 CT simulator and a GE Discovery 750HD CT scanner and their HU values were then measured. The materials with matching HU values of lung (−500 to −700HU), muscle (+40HU) and soft tissue (+100 to +300HU) were further scanned on GE 1.5T Signa HDx to measure their T1 and T2 relaxation times from varying parameters of TI and TE. Results: Materials that could be visualized on T1-weighted and T2-weighted images from a 1.5T MR unit and had an appropriate average CT number, −650, −685, 46,169, and 168 HUs were: compressed cork saturated with water, Polytek Platsil™ Gel-00 combined with mini styrofoam balls, radiotherapy bolus material, SmoothOn Dragon-Skin™ and SmoothOn Ecoflex™, respectively. Conclusion: Post processing analysis is currently being performed to accurately map T1 and T2 values for each material tested. From previous MR visualization and CT examinations it is expected that Dragon-Skin™, Ecoflex™ and bolus will have values consistent with tissue and tumor substitutes. We also expect compressed cork statured with water, and Polytek™-styrofoam combination to have approximate T1 and T2 values suitable for lung-equivalent materials

  10. A High Speed Mobile Courier Data Access System That Processes Database Queries in Real-Time

    Science.gov (United States)

    Gatsheni, Barnabas Ndlovu; Mabizela, Zwelakhe

    A secure high-speed query processing mobile courier data access (MCDA) system for a Courier Company has been developed. This system uses the wireless networks in combination with wired networks for updating a live database at the courier centre in real-time by an offsite worker (the Courier). The system is protected by VPN based on IPsec. There is no system that we know of to date that performs the task for the courier as proposed in this paper.

  11. Chondrogenic Lesions of the Skeletal System Using Radiographs, CT and MRI

    Directory of Open Access Journals (Sweden)

    Akbar Bonakdarpour

    2011-05-01

    Full Text Available Benign Tumors: Chondroma, chondroblastoma,"nchondromyxoid fibroma, osteochondroma"nChondroma"n1. Enchondroma"n2. Periosteal Chondroma"n3. Enchondromatosis"n4. Metachondromatosis"nEnchondroma is a benign metaphyseal tumor. The"nmajor differential diagnoses are bone infarct and"nchondrosarcoma. Calcification in enchondroma"nhas a popcorn appearance and on radiographs and"nCT they may be counted. Calcified bone infarct"nhas an appearance similar to rotten metal. Central"nchondrosarcoma shows cortical erosion more than"ntwo thirds of the thickness of cortex and also periosteal"nreaction. Pain and growth of lesion in adulthood raises"nthe possibility of malignant transformation."nPeriosteal chondroma: This lesion arises from the"nperiosteum without involving the medullary bone."nThe most common location is the upper humerus."nEnchondromatosis reveals multiple enchondromas,"npredominantly involving one side of the skeleton."nMalignant transformation is the major complication"nof enchondromatosis. In malignant transformation,"nMRI shows that perichondrium is more than 1 cm"nthick in adults and more than 3 cm thick in children."nIn the hands and feet, enchondromatosis should not"nbe confused with fibrous dysplasia. Mafucci syndrome"nis enchondromatosis associated with cavernous"nhemangiomas with a prognosis worse than enchondr"nomatosis."nMultiple hereditary cartilaginous exostoses: This is"nof metaphyseal origin and pedunculated forms grow"naway from the adjacent joint. Sessile osteochondromas"nare broad based; if their surface is irregular they are"nsuspicious of malignancy. Pain and growth of the"nlesion after closure of the epiphyseal plate are warning"nsigns of malignant transformation. In malignant"ntransformation MRI shows that perichondrium is"nmore than 1 cm thick in adults and more than 3 cm"nthick in children."nChondroblastoma: This is a benign tumor, seen before"nclosure of epiphyseal plate, with a sclerotic border."n30 to 50% show

  12. Fast Transit Access to the Outer Solar System

    Science.gov (United States)

    Squire, Jared; Bering, Edgar; Giambusso, Matthew; Carter, Mark; Ilin, Andrew; Diaz, Franklin R. Chang

    2015-11-01

    We explore the capability of a VASIMR® reusable probe “catapult” concept to send a 4000-5000 kg spacecraft to Jupiter on a Hohmann-like transfer orbit, arriving in just 36 months elapsed time. The VASIMR® performs a slingshot pass close to the Sun and uses the high level of available solar energy to produce a sustained burst of high thrust. Enough kinetic energy is provided to the probe to reach Jupiter orbit within 0.7-1.4 AU. The Catapult release the probe with enough speed to reach Jupiter in three years, and returns to Earth for another mission. This study identifies the important parameters in the probe ejector operation (power level, propellant mass, payload release point, distance of closest approach to the Sun), and scan these parameters to understand and optimize the capabilities of the proposed system. We assume that the Catapult and its payload begin at the Earth’s sphere of influence (SOI), and are coasting in the Earth’s orbit about the Sun. The VASIMR® engine’s power rating must match the peak power available when the spacecraft is closest to the Sun. The solar array is assumed to be a planar array rather than a concentrator since it will have to operate near the Sun, where a concentrator would overheat photovoltaic cells. The feasibility of not releasing the payload and using the VASIMR® to provide thrust for the duration of the transfer orbit will also be examined. In this scenario, the VASIMR® RF generators could serve double duty as radar RF sources.

  13. Performance Evaluation of Virtualization Techniques for Control and Access of Storage Systems in Data Center Applications

    Science.gov (United States)

    Ahmadi, Mohammad Reza

    2013-09-01

    Virtualization is a new technology that creates virtual environments based on the existing physical resources. This article evaluates effect of virtualization techniques on control servers and access method in storage systems [1, 2]. In control server virtualization, we have presented a tile based evaluation based on heterogeneous workloads to compare several key parameters and demonstrate effectiveness of virtualization techniques. Moreover, we have evaluated the virtualized model using VMotion techniques and maximum consolidation. In access method, we have prepared three different scenarios using direct, semi-virtual, and virtual attachment models. We have evaluated the proposed models with several workloads including OLTP database, data streaming, file server, web server, etc. Results of evaluation for different criteria confirm that server virtualization technique has high throughput and CPU usage as well as good performance with noticeable agility. Also virtual technique is a successful alternative for accessing to the storage systems especially in large capacity systems. This technique can therefore be an effective solution for expansion of storage area and reduction of access time. Results of different evaluation and measurements demonstrate that the virtualization in control server and full virtual access provide better performance and more agility as well as more utilization in the systems and improve business continuity plan.

  14. Digital Model of Human Lower Extremity Musculoskeletal System Based on CT & MRI

    Institute of Scientific and Technical Information of China (English)

    尚鹏; 王成焘; 王立

    2004-01-01

    A new method to reconstruct a comparatively complete muscle model of the human lower limb from CT and MRI data is presented. Topological structure of more than fourteen muscles is built and coordinates of origin and insertion points are given.Based on this model, straight-line model and centroid-line muscle model are acquired. Muscle force prediction is discussed according to the model reconstructed, and a multi-objective optimization method is put forward for evaluating muscle forces of the human lower extremity.

  15. MRI of intracranial calcifications

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jin Wha; Chang, Kee Hyun; Park, Jung Mi; Han, Moon Hee; Han, Man Chung; Kim, Chu Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1988-12-15

    Recently computed tomography(CT) has been rapidly replaced by magnetic resonance imaging (MRI) in diagnosis of majority of intracranial diseases. But MRI still has some limitation, one of which is its inferiority in detecting calcification. MRI of intracranial calcification has been known to be variable in signal intensity. We retrospectively analyzed the MRI of 26 patients with intracranial calcified lesions in order to evaluate the MR intensity of calcification and to assess the capability of MRI in detecting calcification in various intracranial lesions. All the MRI were obtained using routine T1-and T2-weighted spin eco pulse sequences on 2.0T superconducting system. The 26 patients consisted of 13 brain tumors (4 oligodendrogliomas, 2 craniopharyngiomas, 2 astrocytomas, 1 gem cell tumor, 1 medulloblastoma, 1 ependympma, and pathologically unconfirmed 2 cases), 11 infectious diseases (1 paragonimiasis, 1 sparganosis, 2 cysticercosis, 3 tuberculosis, and 4 unknown cases), and 2 undetermined pathologies. Eighty-two percent (9/11) of infections disease, and 50% (1/2) of undetermined group showed signal diminution or signal void on both T1-and T2-weighted image (T1W1, T2W1). Twenty-four percent (3/13) of brain tumors showed signal diminution on both T1W1 and T2W1. In 46% (6/13) and 61% (8/13) of brain tumors the signal intensities were isointense on T1W1 and T1W1, respectively. Unexpectedly, 3 oligodendrogliomas showed high signal intensity on T1W1, two of which showed com plexed signal intensity mixed with high, iso, and low signal intensities on T2W1. In remained cases (18% (2/11) of infectious diseases and 50% (1/2) of undetermined group) the signal intensities were mixed. With simultaneous review of CT and MRI in each case, the calcification (at least one in cases showing multiple ones) was identifiable on MRI in 62% (8/13) of rumors, 82% (9/11) of infectious diseases, and 100% (2/2) in undetermined group. In 36% (4/11) of infectious diseases, fewer number of

  16. Accessing Multi-Source Geological Data through Network in MORPAS Software System

    Institute of Scientific and Technical Information of China (English)

    Mei Hongbo; Hu Guangdao; Chen Jianguo; Li Zhenhua

    2003-01-01

    MORPAS is a special GIS (geographic information system) software system, based on the MAPGIS platform whose aim is to prospect and evaluate mineral resources quantificationally by synthesizing geological, geophysical, geochemical and remote sensing data. It overlays geological database management, geological background and geological abnormality analysis, image processing of remote sensing and comprehensive abnormality analysis, etc.. It puts forward an integrative solution for the application of GIS in basic-level units and the construction of information engineering in the geological field. As the popularization of computer networks and the request of data sharing, it is necessary to extend its functions in data management so that all its data files can be accessed in the network server. This paper utilizes some MAPGIS functions for the second development and ADO (access data object) technique to access multi-source geological data in SQL Server databases. Then remote visiting and congruous management will be realized in the MORPAS system.

  17. A test bed for the future access control system the AD Project

    CERN Document Server

    Scibile, L

    1999-01-01

    This paper describes the design, management and development of the new access control system for the Antiproton Deceleration experimental area, called the AD Project. As this project includes all the elements for the industrial evolution of the present access control system it is an ideal test bed for future access systems. The adoption of new technologies and techniques are described, and the benefits and the shortfalls are highlighted. The open redundant architecture solution, based on a PROFIBUS network and standard industrial components (HP-UNIX, Siemens S7 PLC, Siemens Industrial PC, door locks), guarantees reliability, safety and optimal integration. The project team took advantage of the Goal Directed Project Management technique and managed to define a clear and effective strategy.

  18. Japan Meteorological Agency/Meteorological Research Institute-Coupled Prediction System version 1 (JMA/MRI-CPS1) for operational seasonal forecasting

    Science.gov (United States)

    Takaya, Yuhei; Yasuda, Tamaki; Fujii, Yosuke; Matsumoto, Satoshi; Soga, Taizo; Mori, Hirotoshi; Hirai, Masayuki; Ishikawa, Ichiro; Sato, Hitoshi; Shimpo, Akihiko; Kamachi, Masafumi; Ose, Tomoaki

    2016-04-01

    This paper describes the operational seasonal prediction system of the Japan Meteorological Agency (JMA), the Japan Meteorological Agency/Meteorological Research Institute-Coupled Prediction System version 1 (JMA/MRI-CPS1), which was in operation at JMA during the period between February 2010 and May 2015. The predictive skill of the system was assessed with a set of retrospective seasonal predictions (reforecasts) covering 30 years (1981-2010). JMA/MRI-CPS1 showed reasonable predictive skill for the El Niño-Southern Oscillation, comparable to the skills of other state-of-the-art systems. The one-tiered approach adopted in JMA/MRI-CPS1 improved its overall predictive skills for atmospheric predictions over those of the two-tiered approach of the previous uncoupled system. For 3-month predictions with a 1-month lead, JMA/MRI-CPS1 showed statistically significant skills in predicting 500-hPa geopotential height and 2-m temperature in East Asia in most seasons; thus, it is capable of providing skillful seasonal predictions for that region. Furthermore, JMA/MRI-CPS1 was superior overall to the previous system for atmospheric predictions with longer (4-month) lead times. In particular, JMA/MRI-CPS1 was much better able to predict the Asian Summer Monsoon than the previous two-tiered system. This enhanced performance was attributed to the system's ability to represent atmosphere-ocean coupled variability over the Indian Ocean and the western North Pacific from boreal winter to summer following winter El Niño events, which in turn influences the East Asian summer climate through the Pacific-Japan teleconnection pattern. These substantial improvements obtained by using an atmosphere-ocean coupled general circulation model underpin its success in providing more skillful seasonal forecasts on an operational basis.

  19. An Intelligent System Proposal for Improving the Safety and Accessibility of Public Transit by Highway

    Directory of Open Access Journals (Sweden)

    Carmelo R. García

    2015-08-01

    Full Text Available The development of public transit systems that are accessible and safe for everyone, including people with special needs, is an objective that is justified from the civic and economic points of view. Unfortunately, public transit services are conceived for people who do not have reduced physical or cognitive abilities. In this paper, we present an intelligent public transit system by highway with the goal of facilitating access and improving the safety of public transit for persons with special needs. The system is deployed using components that are commonly available in transport infrastructure, e.g., sensors, mobile communications systems, and positioning systems. In addition, the system can operate in non-urban transport contexts, e.g., isolated rural areas, where the availability of basic infrastructure, such as electricity and communications infrastructures, is not always guaranteed. To construct the system, the principles and techniques of Ubiquitous Computing and Ambient Intelligence have been employed. To illustrate the utility of the system, two cases of services rendered by the system are described: the first case involves a surveillance system to guarantee accessibility at bus stops; the second case involves a route assistant for blind people.

  20. An Intelligent System Proposal for Improving the Safety and Accessibility of Public Transit by Highway.

    Science.gov (United States)

    García, Carmelo R; Quesada-Arencibia, Alexis; Cristóbal, Teresa; Padrón, Gabino; Pérez, Ricardo; Alayón, Francisco

    2015-08-18

    The development of public transit systems that are accessible and safe for everyone, including people with special needs, is an objective that is justified from the civic and economic points of view. Unfortunately, public transit services are conceived for people who do not have reduced physical or cognitive abilities. In this paper, we present an intelligent public transit system by highway with the goal of facilitating access and improving the safety of public transit for persons with special needs. The system is deployed using components that are commonly available in transport infrastructure, e.g., sensors, mobile communications systems, and positioning systems. In addition, the system can operate in non-urban transport contexts, e.g., isolated rural areas, where the availability of basic infrastructure, such as electricity and communications infrastructures, is not always guaranteed. To construct the system, the principles and techniques of Ubiquitous Computing and Ambient Intelligence have been employed. To illustrate the utility of the system, two cases of services rendered by the system are described: the first case involves a surveillance system to guarantee accessibility at bus stops; the second case involves a route assistant for blind people.

  1. Intelligent Voice-Based Door Access Control System Using Adaptive-Network-based Fuzzy Inference Systems (ANFIS for Building Security

    Directory of Open Access Journals (Sweden)

    Wahyudi

    2007-01-01

    Full Text Available Secure buildings are currently protected from unauthorized access by a variety of devices. Even though there are many kinds of devices to guarantee the system safety such as PIN pads, keys both conventional and electronic, identity cards, cryptographic and dual control procedures, the people voice can also be used. The ability to verify the identity of a speaker by analyzing speech, or speaker verification, is an attractive and relatively unobtrusive means of providing security for admission into an important or secured place. An individual’s voice cannot be stolen, lost, forgotten, guessed, or impersonated with accuracy. Due to these advantages, this paper describes design and prototyping a voice-based door access control system for building security. In the proposed system, the access may be authorized simply by means of an enrolled user speaking into a microphone attached to the system. The proposed system then will decide whether to accept or reject the user’s identity claim or possibly to report insufficient confidence and request additional input before making the decision. Furthermore, intelligent system approach is used to develop authorized person models based on theirs voice. Particularly Adaptive-Network-based Fuzzy Inference Systems is used in the proposed system to identify the authorized and unauthorized people. Experimental result confirms the effectiveness of the proposed intelligent voice-based door access control system based on the false acceptance rate and false rejection rate.

  2. Quality Test Template toward Multi-user Access Control of Internet-Based System

    Directory of Open Access Journals (Sweden)

    Nan Nie

    2011-06-01

    Full Text Available Aiming at three kinds of Internet-based system quality problems, which is performance, liability and security, the paper proposes a kind of test template during multi-user login and resource access control, which includes test requirement, login script, role-resource correlating and mutation test technique. Some Internet-based systems are tested and diagnosed by automation test technique of test template. At last, system quality can be verified and improved through the realization mechanism of test template.

  3. Analysis of Coded FHSS Systems with Multiple Access Interference over Generalized Fading Channels

    OpenAIRE

    Zummo SalamA

    2008-01-01

    Abstract We study the effect of interference on the performance of coded FHSS systems. This is achieved by modeling the physical channel in these systems as a block fading channel. In the derivation of the bit error probability over Nakagami fading channels, we use the exact statistics of the multiple access interference (MAI) in FHSS systems. Due to the mathematically intractable expression of the Rician distribution, we use the Gaussian approximation to derive the error probability of coded...

  4. Transparent image access in a distributed picture archiving and communications system: The master database broker

    OpenAIRE

    Cox, R D; Henri, C. J.; Rubin, R. K.

    1999-01-01

    A distributed design is the most cost-effective system for small- to medium-scale picture archiving and communications systems (PACS) implementations. However, the design presents an interesting challenge to developers and implementers: to make stored image data, distributed throughout the PACS network, appear to be centralized with a single access point for users. A key component for the distributed system is a central or master database, containing all the studies that have been scanned int...

  5. MRI pattern of arthritis in systemic lupus erythematosus: a comparative study with rheumatoid arthritis and healthy subjects

    Energy Technology Data Exchange (ETDEWEB)

    Tani, Chiara; Possemato, Niccolo; Delle Sedie, Andrea; Bombardieri, Stefano; Mosca, Marta [University of Pisa, Rheumatology Unit, Department of Clinical and Experimental Medicine, Pisa (Italy); D' aniello, Dario; Caramella, Davide [Radiology Unit, University of Pisa, Pisa (Italy)

    2014-10-24

    In this study we aimed to describe the magnetic resonance imaging (MRI) pattern of the distribution of bone marrow edema (BME) and joint erosion in hands and wrists of patients with systemic lupus erythematosus (SLE) with arthritis in comparison with rheumatoid arthritis (RA) and healthy subjects (H). SLE patients with arthritis (n = 50), patients with RA (n = 22), and H (n = 48) were enrolled. Every patient underwent a non-dominant hand (2nd-5th metacarpophalangeal joints) and wrist MRI without contrast injection with a low-field extremity dedicated 0.2-Tesla instrument. BME was observed in two SLE patients in the hand (4 %) and in 15 in the wrist (13 %) versus three (30 %), and 14 (63 %) RA patients. No BME was found in H. Erosions were observed in the hand in 24 SLE patients (48 %), 15 RA patients (68 %), and 9 H (18 %); in the wrist, in 41 (82 %) SLE, all RA and 47 (97 %) H. The cumulative erosive burden in SLE was significantly higher than in H (c = 0.002) but similar to RA patients. Joint involvement of the wrist in SLE is similar to RA and is not as rare as expected, as shown by the comparison with healthy subjects. On the contrary, the involvement of the hand in SLE is significantly lower compared to RA. (orig.)

  6. A double-blind, comparative study of gadodiamide injection and gadopentetate dimeglumine in MRI of the central nervous system

    International Nuclear Information System (INIS)

    Seventy-nine patients with known or suspected central nervous system lesions were studied with MRI in a phase III double-blind study. Forty were given gadopentetate dimeglumine (Gd-DTPA) and 39 gadodiamide injection (Gd-DTPA BMA), a new low-osmolar nonionic contrast enhancing medium. The dosage was 0.1 mmol/kg body weight, corresonding to 0.2 ml/kg. Spin-echo sequences were performed before and immediately after injection. The safety and efficacy of the two contrast media were assessed. No changes were observed in blood pressure, heart rate or neurological status. Five adverse effects (two episodes of headaches, two of nausea and one of dizziness) were reported by 2 patients who received gadodiamide injection and 1 who received gadopentetate dimeglumine. All events were mild and their relationship to the contrast media was uncertain. Fore both contrast media statistically significant changes in serum iron were observed 24 h after injection. More than 70% of the patients had abnormal findings on MRI, and in 56% of these contrast enhancement of the abnormal structure or lesion was seen. Contrast enhancement provided the diagnosis in about 50%, changed it in 40% and increased diagnostic confidence in 95%. (orig.)

  7. Bus Access Optimization for Distributed Embedded Systems Based on Schedulability Analysis

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2000-01-01

    We present an approach to bus access optimization and schedulability analysis for the synthesis of hard real-time distribution embedded systems. The communication model is based on a time-triggered protocol. We have developed an analysis for the communication delays proposing four different messa...... scheduling policies over a time-triggered communication channel. Optimization strategies for the bus access scheme are developed, and the four approaches to message scheduling are compared using extensive experiments.......We present an approach to bus access optimization and schedulability analysis for the synthesis of hard real-time distribution embedded systems. The communication model is based on a time-triggered protocol. We have developed an analysis for the communication delays proposing four different message...

  8. Optimizing man-machine performance of a personnel access restriction security system

    International Nuclear Information System (INIS)

    This paper describes a human engineering design and analysis effort for a major security system upgrade at a DOE facility. This upgrade was accomplished by replacing an obsolete and poorly human engineered security screening both the with a new, user oriented, semiautomated, computer-based access control system. Human factors engineers assisted the designer staff in specifying a security access interface to physically and cognitively accommodate all employees which included handicapped individuals in wheel chairs, and several employees who were severely disabled, both visually and aurally. The new access system was intended to control entry into sensitive exclusion areas by requiring personnel to enter a security screening booth and interact with card reader devices and a-simple-to-operate access control panel system. Extensive man-machine testing with prototype mock-ups was conducted to assess human engineered design features and to illuminate potentially confusing or difficult-to-operated hardware placement, layout, and operation sequencing. These evaluations, along with the prototype mock-ups, provided input which resulted in a prototype which was easy to enter, operate, and understand by end users. This prototype later served as the design basis for the final systems design

  9. 49 CFR 37.185 - Fleet accessibility requirement for OTRB fixed-route systems of large operators.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Fleet accessibility requirement for OTRB fixed....185 Fleet accessibility requirement for OTRB fixed-route systems of large operators. Each large... percent of the buses in its fleet with which it provides fixed-route service are readily accessible to...

  10. OASIS: A Data Fusion System Optimized for Access to Distributed Archives

    Science.gov (United States)

    Berriman, G. B.; Kong, M.; Good, J. C.

    2002-05-01

    The On-Line Archive Science Information Services (OASIS) is accessible as a java applet through the NASA/IPAC Infrared Science Archive home page. It uses Geographical Information System (GIS) technology to provide data fusion and interaction services for astronomers. These services include the ability to process and display arbitrarily large image files, and user-controlled contouring, overlay regeneration and multi-table/image interactions. OASIS has been optimized for access to distributed archives and data sets. Its second release (June 2002) provides a mechanism that enables access to OASIS from "third-party" services and data providers. That is, any data provider who creates a query form to an archive containing a collection of data (images, catalogs, spectra) can direct the result files from the query into OASIS. Similarly, data providers who serve links to datasets or remote services on a web page can access all of these data with one instance of OASIS. In this was any data or service provider is given access to the full suite of capabilites of OASIS. We illustrate the "third-party" access feature with two examples: queries to the high-energy image datasets accessible from GSFC SkyView, and links to data that are returned from a target-based query to the NASA Extragalactic Database (NED). The second release of OASIS also includes a file-transfer manager that reports the status of multiple data downloads from remote sources to the client machine. It is a prototype for a request management system that will ultimately control and manage compute-intensive jobs submitted through OASIS to computing grids, such as request for large scale image mosaics and bulk statistical analysis.

  11. MRI Findings In Dengue Encephalitis

    Directory of Open Access Journals (Sweden)

    Ashraf V.V

    2004-01-01

    Full Text Available Neurological manifestations are rare in dengue fever. Two cases with encephalopathy and systemic features of dengue fever with abnormal CSF and MR imaging are reported. Striking MRI finding was bilateral symmetrical thalamic lesions similar to those reported in Japanese encephalitis. This report highlights that MRI findings can be similar in dengue and Japanese encephalitis.

  12. High security chaotic multiple access scheme for visible light communication systems with advanced encryption standard interleaving

    Science.gov (United States)

    Qiu, Junchao; Zhang, Lin; Li, Diyang; Liu, Xingcheng

    2016-06-01

    Chaotic sequences can be applied to realize multiple user access and improve the system security for a visible light communication (VLC) system. However, since the map patterns of chaotic sequences are usually well known, eavesdroppers can possibly derive the key parameters of chaotic sequences and subsequently retrieve the information. We design an advanced encryption standard (AES) interleaving aided multiple user access scheme to enhance the security of a chaotic code division multiple access-based visible light communication (C-CDMA-VLC) system. We propose to spread the information with chaotic sequences, and then the spread information is interleaved by an AES algorithm and transmitted over VLC channels. Since the computation complexity of performing inverse operations to deinterleave the information is high, the eavesdroppers in a high speed VLC system cannot retrieve the information in real time; thus, the system security will be enhanced. Moreover, we build a mathematical model for the AES-aided VLC system and derive the theoretical information leakage to analyze the system security. The simulations are performed over VLC channels, and the results demonstrate the effectiveness and high security of our presented AES interleaving aided chaotic CDMA-VLC system.

  13. NOTE: MRI-guided robotic system for transperineal prostate interventions: proof of principle

    Science.gov (United States)

    van den Bosch, Michiel R.; Moman, Maaike R.; van Vulpen, Marco; Battermann, Jan J.; Duiveman, Ed; van Schelven, Leonard J.; de Leeuw, Hendrik; Lagendijk, Jan J. W.; Moerland, Marinus A.

    2010-03-01

    In this study, we demonstrate the proof of principle of the University Medical Center Utrecht (UMCU) robot dedicated to magnetic resonance imaging (MRI)-guided interventions in patients. The UMCU robot consists of polymers and non-ferromagnetic materials. For transperineal prostate interventions, it can be placed between the patient's legs inside a closed bore 1.5T MR scanner. The robot can manually be translated and rotated resulting in five degrees of freedom. It contains a pneumatically driven tapping device to automatically insert a needle stepwise into the prostate using a controller unit outside the scanning room. To define the target positions and to verify the needle insertion point and the needle trajectory, a high-resolution 3D balanced steady state free precession (bSSFP) scan that provides a T2/T1-weighted contrast is acquired. During the needle insertion fast 2D bSSFP images are generated to track the needle on-line. When the target position is reached, the radiation oncologist manually places a fiducial gold marker (small seed) at this location. In total two needle trajectories are used to place all markers. Afterwards, a high-resolution 3D bSSFP scan is acquired to visualize the fiducial gold markers. Four fiducial gold markers were placed transperineally into the prostate of a patient with a clinical stage T3 prostate cancer. In the generated scans, it was possible to discriminate the patient's anatomy, the needle and the markers. All markers were delivered inside the prostate. The procedure time was 1.5 h. This study proves that MRI-guided needle placement and seed delivery in the prostate with the UMCU robot are feasible.

  14. The upgrade of the J-TEXT experimental data access and management system

    International Nuclear Information System (INIS)

    Highlights: • The J-TEXT DAMS is developed based on B/S model, which makes it conveniently access the system. • The JWeb-Scope adopts segment strategy to read data that improve the speed of reading data. • DAMS have integrated the management and JWeb-Scope and make an easy way for visitors to access the experiment data. • The JWeb-Scope can be visited all over the world, plot experiment data and zoom in or out smoothly. - Abstract: The experimental data of J-TEXT tokamak are stored in the MDSplus database. The old J-TEXT data access system is based on the tools provided by MDSplus. Since the number of signals is huge, the data retrieval for an experiment is difficult. To solve this problem, the J-TEXT experimental data access and management system (DAMS) based on MDSplus has been developed. The DAMS left the old MDSplus system unchanged providing new tools, which can help users to handle all signals as well as to retrieve signals they need thanks to the user information requirements. The DAMS also offers users a way to create their jScope configuration files which can be downloaded to the local computer. In addition, the DAMS provides a JWeb-Scope tool to visualize the signal in a browser. JWeb-Scope adopts segment strategy to read massive data efficiently. Users can plot one or more signals on their own choice and zoom-in, zoom-out smoothly. The whole system is based on B/S model, so that the users only need of the browsers to access the DAMS. The DAMS has been tested and it has a better user experience. It will be integrated into the J-TEXT remote participation system later

  15. 28 CFR 16.92 - Exemption of Environment and Natural Resources Division Systems-limited access.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of Environment and Natural....92 Exemption of Environment and Natural Resources Division Systems—limited access. (a)(1) The...) Environment and Natural Resources Division Case and Related Files System, JUSTICE/ENRD-003. (ii) (2)...

  16. Accessibility Evaluation of Online Learning Management System for Persons with Visual Impairment

    Science.gov (United States)

    Suwannawut, Nantanoot

    2014-01-01

    Many academic institutions around the world are utilizing and investing in online learning management systems (LMS). While several research studies have examined the functionality of this type of technology, little attention has been paid to accessibility issues, in particular to the complex web-based interfaces for learners with disabilities,…

  17. Centralized optical-frequency-comb-based RF carrier generator for DWDM fiber-wireless access systems

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Beltran, Marta; Sanchez, Jose;

    2014-01-01

    In this paper, we report on a gigabit capacity fiber-wireless system that enables smooth integration between high-speed wireless networks and dense wavelength-division-multiplexing (DWDM) access networks. By employing a centralized optical frequency comb, both the wireline and the wireless services...

  18. Crop Status Monitoring using Multispectral and Thermal Imaging systems for Accessible Aerial Platforms

    Science.gov (United States)

    Agricultural aircraft and unmanned aerial systems (UAS) are easily scheduled and accessible remote sensing platforms. Canopy temperature data were taken with an Electrophysics PV-320T thermal imaging camera mounted in agricultural aircraft. Weather data and soil water potential were monitored and th...

  19. 28 CFR 16.93 - Exemption of Tax Division Systems-limited access.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of Tax Division Systems-limited access. 16.93 Section 16.93 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE OF... concerning the nature of that investigation and the information obtained, and to determine the identity...

  20. 28 CFR 16.77 - Exemption of U.S. Trustee Program System-limited access.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of U.S. Trustee Program System-limited access. 16.77 Section 16.77 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE... existence of a confidential investigation or reveal the identity of witnesses or confidential informants....

  1. 28 CFR 16.80 - Exemption of Office of Professional Responsibility System-limited access.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of Office of Professional Responsibility System-limited access. 16.80 Section 16.80 Judicial Administration DEPARTMENT OF JUSTICE... obtained as to his activities; of the identity of confidential sources, witnesses, and law...

  2. 28 CFR 16.88 - Exemption of Antitrust Division Systems-limited access.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of Antitrust Division Systems-limited access. 16.88 Section 16.88 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE... and compiled for law enforcement purposes could result in the premature disclosure of the identity...

  3. 75 FR 47464 - Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control...

    Science.gov (United States)

    2010-08-06

    ... Copyright Office 37 CFR Part 201 Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control Technologies AGENCY: Copyright Office, Library of Congress. ACTION: Final Rule; correction. SUMMARY: The Copyright Office makes a nonsubstantial correction to its regulation announcing...

  4. An API-based search system for one click access to information

    NARCIS (Netherlands)

    Ionita, Dan; Tax, Niek; Hiemstra, Djoerd

    2013-01-01

    This paper proposes a prototype One Click access system, based on previous work in the field and the related 1CLICK-2@NTCIR10 task. The proposed solution integrates methods from into a three tier algorithm: query categorization, information extraction and output generation and offers suggestions on

  5. Hacking Blackboard: Customizing Access to Library Resources through the Blackboard Course Management System

    Science.gov (United States)

    Kellam, Lynda M.; Cox, Richard; Winkler, Hannah

    2009-01-01

    Academic libraries have long been trying to gain access to users through their favorite online spaces, such as social networking sites. In this article a project of the University of North Carolina at Greensboro's University Libraries, which integrated library resources with the campus course management system, Blackboard, is detailed. The main…

  6. MRI Safety during Pregnancy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z MRI Safety During Pregnancy Magnetic resonance imaging (MRI) Illness ... during the exam? Contrast material MRI during pregnancy Magnetic resonance imaging (MRI) If you are pregnant and your doctor ...

  7. Email based remote access and surveillance system for smart home infrastructure

    Directory of Open Access Journals (Sweden)

    Pooshkar Rajiv

    2016-09-01

    Full Text Available With the rapid rise of Internet of Things in public domain, people expect fast, reliable and on-demand home security via the Internet. However, existing remote home surveillance systems place a very rigid constraint on authentication and require customized hardware and software. In this paper we have proposed an ingenious and reliable internet based, home access system for smart homes that can be easily deployed on generic hardware. The proposed architecture uses popular email service providers to notify and update the user about the home access. It sends an email to the owner with the attached picture of the person who is at the door. It also incorporates a protected mechanism to give access of the door to a remote user by responding to that email. It essentially means that we can view and give access to the person at our door via sending and receiving an email. Furthermore, an image processing based mechanism has also been incorporated to provide access without email, to few selected personnel who are trusted by the owner. It works by capturing and comparing the visitor's image with the stored images in the database. Perceptual hashing or fingerprint matching algorithm is used for comparison purposes. Similarity percentage based on hamming distance was evaluated, and the similarity threshold for providing access was set. The simulations were performed in rigorous environment. The efficiency of the hashing algorithm was found to be 97% at the similarity threshold of 95%. The results validate that the average latency is only 155 ms with low standard deviation. The CPU utilization remained quite low with a minimum value of 10 MHz and a maximum value of 30 MHz when the payload size of the sent mail was increased to 1500 kB. Thus, the proposed system can be used for developing a larger low power infrastructure.

  8. Design and Implementation of File Access and Control System Based on Dynamic Web

    Institute of Scientific and Technical Information of China (English)

    GAO Fuxiang; YAO Lan; BAO Shengfei; YU Ge

    2006-01-01

    A dynamic Web application, which can help the departments of enterprise to collaborate with each other conveniently, is proposed. Several popular design solutions are introduced at first. Then, dynamic Web system is chosen for developing the file access and control system. Finally, the paper gives the detailed process of the design and implementation of the system, which includes some key problems such as solutions of document management and system security. Additionally, the limitations of the system as well as the suggestions of further improvement are also explained.

  9. Guide on Project Web Access of SFR R and D and Technology Monitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Uk; Won, Byung Chool; Lee, Yong Bum; Kim, Young In; Hahn, Do Hee

    2008-09-15

    The SFR R and D and technology monitoring system based on the MS enterprise project management is developed for systematic effective management of 'Development of Basic Key Technologies for Gen IV SFR' project which was performed under the Mid- and Long-term Nuclear R and D Program sponsored by the Ministry of Education, Science and Technology. This system is a tool for project management based on web access. Therefore this manual is a detailed guide for Project Web Access(PWA). Section 1 describes the common guide for using of system functions such as project server 2007 client connection setting, additional outlook function setting etc. The section 2 describes the guide for system administrator. It is described the guide for project management in section 3, 4.

  10. Guide on Project Web Access of SFR R and D and Technology Monitoring System

    International Nuclear Information System (INIS)

    The SFR R and D and technology monitoring system based on the MS enterprise project management is developed for systematic effective management of 'Development of Basic Key Technologies for Gen IV SFR' project which was performed under the Mid- and Long-term Nuclear R and D Program sponsored by the Ministry of Education, Science and Technology. This system is a tool for project management based on web access. Therefore this manual is a detailed guide for Project Web Access(PWA). Section 1 describes the common guide for using of system functions such as project server 2007 client connection setting, additional outlook function setting etc. The section 2 describes the guide for system administrator. It is described the guide for project management in section 3, 4

  11. Combinatory Spread—Spectrum Multiple—Access Based on Residue Number System:System and Performance

    Institute of Scientific and Technical Information of China (English)

    YangLieliang; LiChengshu

    1995-01-01

    A combinatory direct-sequence based on residue number system(RNS),spread spec-trum multiple-access communication system model is presented.Under this communication envi-ronment,each user is assigned a set of∑i=1lmi(when i≠j,gcd(mi,mj)=1)othogonal sequences;Each receiver has ∑i=1l micorrelators used for despread,log2(пi=1lmi) information bits can be trans-mitted in a symbol period.We obtain approximations for the multiuser probability of error when the channel noise is a combination of additive white Gaussian noise (AWGN)and multiple-access interference .In section4,we compare the performance such as transmission capability,system structure,and the probability of error with the system proposed by P.K.Enge.

  12. Design of a conduction-cooled 9.4 T REBCO magnet for whole-body MRI systems

    Science.gov (United States)

    Miyazaki, Hiroshi; Iwai, Sadanori; Otani, Yasumi; Takahashi, Masahiko; Tosaka, Taizo; Tasaki, Kenji; Nomura, Shunji; Kurusu, Tsutomu; Ueda, Hiroshi; Noguchi, So; Ishiyama, Atsushi; Urayama, Shinichi; Fukuyama, Hidenao

    2016-10-01

    A project on the development of REBa2Cu3O7-δ (REBCO) magnets for ultra-high-field magnetic resonance imaging (MRI) was started in 2013. Since REBCO-coated conductors feature high mechanical strength under tensile stress and high critical current density, use of REBCO coils would allow superconducting magnets to be made smaller and lighter than conventional ones. In addition, a conduction-cooled superconducting magnet is simpler to use than one cooled by a liquid helium bath because the operation and maintenance of the cryogenic system become simpler, without the need to handle cryogenic fluid. Superconducting magnets for MRI require homogeneous, stable magnetic fields. The homogeneity of the magnetic field is highly dependent on the coil shape and position. Moreover, in REBCO magnets, the screening-current-induced magnetic field, which changes the magnetic field distribution of the magnet, is one of the critical issues. In order to evaluate the magnetic field homogeneity and the screening-current-induced magnetic field, a 1 T model magnet and some test coils were fabricated. From an evaluation of the 1 T model magnet, it was found that the main reason for magnetic field inhomogeneity was the tolerances in the z-axis positions of the coils, and therefore, it is important to control the gap between the single pancakes. In addition, we have already demonstrated the generation of an 8.27 T central magnetic field at 10 K with a small test coil. The screening-current-induced magnetic field was 0.43 T and was predictable by using an electromagnetic field simulation program. These results were reflected in the design of a conduction-cooled 9.4 T REBCO magnet for whole-body MRI systems. The magnet was composed of six main coils and two active shield coils. The total conductor length was 581 km, and the stored energy was 293 kJ. The field inhomogeneity was 24 ppm peak to peak and 3 ppm volume-root-mean-square (VRMS) for a 500 mm diameter spherical volume (DSV). The axial

  13. A Generic Role Based Access Control Model for Wind Power Systems

    DEFF Research Database (Denmark)

    Nagarajan, Anand; Jensen, Christian D.

    2010-01-01

    The electrical power infrastructure is facing a transition from a largely centralised distribution infrastructure with a few large power plants to an increasingly distributed infrastructure that must incorporate privately owned and operated power generation units based on fuel cells or sustainable...... infrastructure in a software domain in a manufacturer independent manner as well as establishing secure communication and authenticating the other parties in electrical power infrastructures, but they do not address the problem of access control. We therefore propose a generic model for access control in wind...... power systems, which is based on the widely used role-based access control model. The proposed model is tested using a prototype designed in conformance with the standards that are in use in modern wind power infrastructure and the results are presented to determine the overhead in communication caused...

  14. A Novel Memory Structure for Embedded Systems: Flexible Sequential and Random Access Memory

    Institute of Scientific and Technical Information of China (English)

    Ying Chen; Karthik Ranganathan; Vasudev V. Pai; David J. Lilja; Kia Bazargan

    2005-01-01

    The on-chip memory performance of embedded systems directly affects the system designers' decision about how to allocate expensive silicon area. A novel memory architecture, flexible sequential and random access memory (FSRAM),is investigated for embedded systems. To realize sequential accesses, small "links" are added to each row in the RAM array to point to the next row to be prefetched. The potential cache pollution is ameliorated by a small sequential access buffer (SAB). To evaluate the architecture-level performance of FSRAM, we ran the Mediabench benchmark programs on a modified version of the SimpleScalar simulator. Our results show that the FSRAM improves the performance of a baseline processor with a 16KB data cache up to 55%, with an average of 9%; furthermore, the FSRAM reduces 53.1% of the data cache miss count on average due to its prefetching effect. We also designed RTL and SPICE models of the FSRAM, which show that the FSRAM significantly improves memory access time, while reducing power consumption, with negligible area overhead.

  15. Difficulties experienced by trans people in accessing the Unified Health System.

    Science.gov (United States)

    Rocon, Pablo Cardozo; Rodrigues, Alexsandro; Zamboni, Jésio; Pedrini, Mateus Dias

    2016-08-01

    The objective of this study was to discuss the difficulties of trans people living in the metropolitan region of Greater Vitória, Espírito Santo, Brazil, in accessing the health services of the Unified Health System (Sistema Único de Saúde - SUS). We used a qualitative approach through semi-structured interviews with 15 trans people. The results point to disrespect toward the adopted name, discrimination, and the diagnosis required for the gender reassignment process as major limitations to accessing the healthcare system. The diagnosis helps hide the responsibility of heteronormativity and gender binarism in the social marginalization of trans people. It is concluded that it is necessary to review the issue of diagnosis, given that the existence of a prior pathology is not required to access the SUS. It is important to develop educational programmes and permanent campaigns concerning the right to access the healthcare system free from discrimination and to use the adopted name. PMID:27557024

  16. MRI in Japanese encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Radiology; Misra, U.K. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Neurology; Kalita, J. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Neurology; Salwani, V. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Radiology; Gupta, R.K. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Radiology; Gujral, R. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Radiology

    1997-03-01

    We document the MRI features in seven patients with Japanese encephalitis. MRI was carried out on a 1.5 T system within 10-60 days of onset. In all the patients MRI revealed bilateral thalamic lesions, haemorrhagic in five. Signal changes were present in the cerebrum in four patients, the midbrain and cerebellum in three each, the pons in two and the basal ganglia in one. The lesions were haemorrhagic in three of the four patients with lesions in the cortex, two of the three with lesions in the midbrain and cerebellum, but the pontine lesions were haemorrhagic in both patients. Spinal cord involvement was seen in one of the three patients who underwent MRI. In two patients MRI was repeated 3 years after the onset, showing marked reduction in abnormal signal; and all the lesions gave low signal on both T1- and T2-weighted images. Bilateral thalamic involvement, especially haemorrhagic, may be considered characteristic of Japanese encephalitis, especially in endemic areas. (orig.)

  17. A new, preoperative, MRI-based scoring system for diagnosing malignant axillary lymph nodes in women evaluated for breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    He, Ni, E-mail: 61684754@qq.com [Department of Medical Imaging and Interventional Radiology, State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou 510060 (China); Xie, Chuanmiao, E-mail: xiechm@sysucc.org.cn [Department of Medical Imaging and Interventional Radiology, State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou 510060 (China); Wei, Weidong, E-mail: weiwd@sysucc.org.cn [Department of Breast, State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou 510060 (China); Pan, Changchuan, E-mail: 1253719670@qq.com [Department of Medical Imaging and Interventional Radiology, State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou 510060 (China); Wang, Wenyan, E-mail: 7344362@qq.com [College of Electronic Engineering, Guangxi Normal University, Guilin 541004 (China); Lv, Ning, E-mail: 409109980@qq.com [Department of Breast, State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou 510060 (China); Wu, Peihong, E-mail: mit@caca.sina.net [Department of Medical Imaging and Interventional Radiology, State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou 510060 (China)

    2012-10-15

    Objective: Malignant axillary lymph nodes are an important predictor for breast cancer recurrence, but invasive dissection or biopsy is required for the diagnosis. We determined whether and how malignant nodes could be diagnosed preoperatively with magnetic resonance (MR) imaging. Materials and methods: We obtained MR images of all women evaluated for breast cancer at the Sun Yat-Sen University Cancer Center in 2010 and correlated the image characteristics of each axillary node with the pathologic diagnosis of the same node. Results: We analyzed 251 nodes (117 benign; 134 malignant) from 136 women (mean age, 44 years; range, 20–67). Mean diameter of the nodes was 18 mm (range, 5–58 mm). With pathologic diagnosis as the reference standard, MRI-based interpretations were 66.4% sensitive, 94% specific, and 79% accurate. Diameter, pathologic type, apparent diffusion coefficient value (ADC, b = 500 and 800), time-intensity curve (TIC) type of breast tumors correlated with node metastasis; ADC value (b = 500 and 800), TIC type, early enhancement rate, long-axis, short-axis, shape, margin and the location of nodes correlated with node metastasis (P < 0.001 for all). Tumor immunohistochemistry results for estrogen receptors, progesterone receptors, c-erbB-2, vascular endothelial growth factor, and Ki67 were not. An MRI-based lymph node scoring system based on these correlations had a specificity of 91%, a sensitivity of 93%, and an area under the ROC curve of 0.95 (P < 0.001). Conclusion: Metastatic axillary lymph nodes can be accurately diagnosed by MR in women with early breast cancer preoperatively and non-invasively. The scoring system appears to be superior to current methods.

  18. Fetal MRI

    International Nuclear Information System (INIS)

    Ultrasonography is the method of choice for prenatal malformation screening, but it does not always provide sufficient information for correct diagnosis or adequate abnormality evaluation. Fetal MRI is increasingly being used to complete sonographic findings. It was initially used for evaluation of cerebral abnormalities but is increasingly being applied to other fetal areas. In vivo investigation of fetal brain maturation has been enhanced by MRI. An adequate analysis of fetal chest and abdomen can be achieved with fast T2-, T1-weighted and diffusion-weighted imaging (DWI). The advantages include the great field of view and the excellent soft tissue contrast. This allows correct diagnosis of congenital diaphragmatic hernia and evaluation of the consequences on pulmonary growth. Other pulmonary malformations, such as cystic adenomatoid malformation, sequestration and brochogenic cysts, can also be easily identified. Renal position can be quickly determined using DWI sequences and renal agenesia can be easily diagnosed with only one sequence. Prenatal MRI is virtually as effective as postnatal examination, dispenses with transport of a potentially very ill newborn, and provides logistic advantages. Therefore, prenatal MRI is useful for adequate postnatal treatment of newborns with malformations. (orig.)

  19. Design and Implementation of a Web-based Monitoring System by using EPICS Channel Access Protocol

    International Nuclear Information System (INIS)

    Proton Engineering Frontier Project (PEFP) has developed a 20MeV proton accelerator, and established a distributed control system based on EPICS for sub-system components such as vacuum unit, beam diagnostics, and power supply system. The control system includes a real-time monitoring and alarm functions. From the aspect of a efficient maintenance of a control system and a additional extension of subsystems, EPICS software framework was adopted. In addition, a control system should be capable of providing an easy access for users and a real-time monitoring on a user screen. Therefore, we have implemented a new web-based monitoring server with several libraries. By adding DB module, the new IOC web monitoring system makes it possible to monitor the system through the web. By integrating EPICS Channel Access (CA) and Database libraries into a Database module, the web-based monitoring system makes it possible to monitor the sub-system status through user's internet browser. In this study, we developed a web based monitoring system by using EPICS IOC (Input Output Controller) with IBM server

  20. Open Access Intellectual Property Systems: A Comparison to Commercial Solutions in Competitive Intelligence

    Directory of Open Access Journals (Sweden)

    Jan Cerny

    2016-07-01

    Full Text Available ICT/IS management plays an important role within the framework of innovation management, and one of the key elements of this role is the support of Competitive Intelligence in the context of innovation processes. The strategic information needs of innovation management are also directed towards different kinds of intellectual property (IP information entities and commercialization. The purpose of this paper is to define these entities and IP information systems as an important part of a company’s Competitive Intelligence Unit for competitor analysis and technology trends. The open access IP information systems will be analysed together with commercial solutions.. The aim of this paper is to underline the importance of open access IP systems compared to added value commercial solutions for competitive intelligence purposes for SMEs. The comparison will be carried out using examples of patent searches within a concrete dataset.

  1. Discovery of abundant, accessible hydrocarbons nearly everywhere in the solar system

    Energy Technology Data Exchange (ETDEWEB)

    Zuppero, A.

    1996-05-01

    analysis of the data gathered during the Comet Halley encounter during 1987 resulted in a body of literature asserting that all comets contain substantial percentages of hydrocarbon solids. These solids appear to have a strong similarity to petrochemicals. Arguments are made that the amount of hydrocarbon material in the accessible comets of the inner Solar system can substantially exceed the known reserves of hydrocarbons on Earth. An example is given of at least one conceptually simple method to use comet material as feedstock for space transportation schemes that can move masses through the solar system comparable to the mass carried by oil supertankers. The presentation concludes we need to send prospecting and assay probes to a sampling of the accessible comets to determine the amount of hydrocarbons and the form and location of materials needed for space transportation systems.

  2. Design of a loop resonator with a split-ring-resonator (SRR) for a human-body coil in 3 T MRI systems

    Science.gov (United States)

    Son, Hyeok Woo; Cho, Young Ki; Kim, Byung Mun; Back, Hyun Man; Yoo, Hyoungsuk

    2016-04-01

    A new radio-frequency (RF) resonator for Nuclear Magnetic Resonance (NMR) imaging at clinical magnetic resonance imaging (MRI) systems is proposed in this paper. An approach based on the effects of the properties of metamaterials in split-ring resonators (SRRs) is used to design a new loop resonator with a SRR for NMR imaging. This loop resonator with a SRR is designed for NMR imaging at 3 T MRI systems. The 3D electromagnetic simulation was used to optimize the design of the proposed RF resonator and analyze it's performance at 3 T MRI systems. The proposed RF resonator provides strong penetrating magnetic fields at the center of the human phantom model, approximately 10%, as compared to the traditional loop-type RF resonator used for NMR imaging at clinical MRI systems. We also designed an 8-channel body coil for human-body NMR imaging by using the proposed loop resonator with a SRR. This body coil also produces more homogeneous and highly penetrating magnetic fields into the human phantom model.

  3. Study of spread spectrum multiple access systems for satellite communications with overlay on current services

    Science.gov (United States)

    Ha, Tri T.; Pratt, Timothy

    1989-05-01

    The feasibility of using spread spectrum techniques to provide a low-cost multiple access system for a very large number of low data terminals was investigated. Two applications of spread spectrum technology to very small aperture terminal (VSAT) satellite communication networks are presented. Two spread spectrum multiple access systems which use a form of noncoherent M-ary FSK (MFSK) as the primary modulation are described and the throughput analyzed. The analysis considers such factors as satellite power constraints and adjacent satellite interference. Also considered is the effect of on-board processing on the multiple access efficiency and the feasibility of overlaying low data rate spread spectrum signals on existing satellite traffic as a form of frequency reuse is investigated. The use of chirp is examined for spread spectrum communications. In a chirp communication system, each data bit is converted into one or more up or down sweeps of frequency, which spread the RF energy across a broad range of frequencies. Several different forms of chirp communication systems are considered, and a multiple-chirp coded system is proposed for overlay service. The mutual interference problem is examined in detail and a performance analysis undertaken for the case of a chirp data channel overlaid on a video channel.

  4. Predictive value of semi-quantitative MRI-based scoring systems for future knee replacement: data from the osteoarthritis initiative

    Energy Technology Data Exchange (ETDEWEB)

    Hafezi-Nejad, Nima; Eng, John; Demehri, Shadpour [Johns Hopkins University School of Medicine, Musculoskeletal Radiology, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Zikria, Bashir [Johns Hopkins University, Department of Orthopedic Surgery, Baltimore, MD (United States); Carrino, John A. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States)

    2015-11-15

    To evaluate, in a confirmatory fashion, whether baseline and change from baseline to 24-month follow-up in cartilage damage, bone marrow lesions and meniscal damage are predictors of knee replacement (KR) in subjects with a high risk of osteoarthritis (OA), independent of the level of physical activity, symptom severity and radiographic abnormalities. Data from the Osteoarthritis Initiative's (OAI) baseline and 24-month follow-up knee MRIs of 115 patients (age range: 45-78 years; 48 % female; BMI: 20.9-48.7) were analyzed. Cartilage, bone marrow and menisci were semi-quantitatively scored according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) and Boston-Leeds Osteoarthritis Knee Score (BLOKS) systems in all compartments. Baseline and 24-month interval changes in structural tissue damage assessed by BLOKS and WORMS were used as predictors of KR independent of clinical and radiographic parameters using Cox hazard analysis. Adjustments were performed for age, gender, BMI and physical activity (Physical Activity Scale for the Elderly: PASE), Western Ontario and McMaster Questionnaire (WOMAC) total score and radiographic Kellgren-Lawrence (KL) score. BLOKS and WORMS baseline cartilage scores were predictors of KR independent of the PASE, WOMAC and KL score. One score increase in the average baseline BLOKS full-thickness cartilage defect score was associated with a [hazard ratio (95 % CI)] 13.55 (3.61-50.89) times greater risk of KR independent of the PASE, WOMAC and KL score. Net reclassification improvements (NRIs) of the additional evaluation of 24-month follow-up MRI scores and assessment of changes were not significant for prediction of KR (NRI range: - 7.23 - 24.8 %). The BLOKS cartilage score for full-thickness cartilage defects had the highest hazard for KR. Follow-up MRI changes in structural tissue damage, detected by BLOKS and WORMS cartilage, bone marrow or meniscus scores (up to 24 months) had no significant predictive value in addition

  5. Return Migrants’ Experience of Access to Care in Corrupt Healthcare Systems: The Bosnian Example

    Directory of Open Access Journals (Sweden)

    Line Neerup Handlos

    2016-09-01

    Full Text Available Equal and universal access to healthcare services is a core priority for a just health system. A key societal determinant seen to create inequality in access to healthcare is corruption in the healthcare system. How return migrants’ access to healthcare is affected by corruption is largely unstudied, even though return migrants may be particularly vulnerable to problems related to corruption due to their period of absence from their country of origin. This article investigates how corruption in the healthcare sector affects access to healthcare for refugees who repatriated to Bosnia, a country with a high level of corruption, from Denmark, a country with a low level of corruption. The study is based on 18 semi-structured interviews with 33 refugees who returned after long-term residence in Denmark. We found that the returned refugees faced greater problems with corruption than was the case for those who had not left the country, as doctors considered them to be better endowed financially and therefore demanded larger bribes from them than they did from those who had remained in Bosnia. Moreover, during their stay abroad the returnees had lost the connections that could have helped them sidestep the corruption. Returned refugees are thus particularly vulnerable to the effects of corruption.

  6. Preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt

    International Nuclear Information System (INIS)

    This report presents results of a study leading to preconceptual designs for plugging boreholes, shafts, and tunnels to a nuclear waste repository in basalt. Beginning design criteria include a list of preferred plug materials and plugging machines that were selected to suit the environmental conditions, and depths, diameters, and orientations of the accesses to a nuclear waste repository in the Columbia River basalts located in eastern Washington State. The environmental conditions are described. The fiscal year 1979-1980 Task II work is presented in two parts: preliminary testing of materials for plugging of man-made accesses to a repository in basalt (described in a separate report); and preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt (described in this report). To fulfill the scope of the Task II work, Woodward-Clyde Consultants (WCC) was requested to: provide preconceptual systems for plugging boreholes, tunnels, and shafts in basalt; describe preconceptual borehole plugging equipment for placing the selected materials in man-made accesses; utilize the quality assurance program, program plan and schedule, and work plans previously developed for Task II; and prepare a preliminary report

  7. Return Migrants’ Experience of Access to Care in Corrupt Healthcare Systems: The Bosnian Example

    Science.gov (United States)

    Neerup Handlos, Line; Fog Olwig, Karen; Bygbjerg, Ib Christian; Norredam, Marie

    2016-01-01

    Equal and universal access to healthcare services is a core priority for a just health system. A key societal determinant seen to create inequality in access to healthcare is corruption in the healthcare system. How return migrants’ access to healthcare is affected by corruption is largely unstudied, even though return migrants may be particularly vulnerable to problems related to corruption due to their period of absence from their country of origin. This article investigates how corruption in the healthcare sector affects access to healthcare for refugees who repatriated to Bosnia, a country with a high level of corruption, from Denmark, a country with a low level of corruption. The study is based on 18 semi-structured interviews with 33 refugees who returned after long-term residence in Denmark. We found that the returned refugees faced greater problems with corruption than was the case for those who had not left the country, as doctors considered them to be better endowed financially and therefore demanded larger bribes from them than they did from those who had remained in Bosnia. Moreover, during their stay abroad the returnees had lost the connections that could have helped them sidestep the corruption. Returned refugees are thus particularly vulnerable to the effects of corruption. PMID:27657096

  8. A Novel Medium Access Control for Ad hoc Networks Based on OFDM System

    Institute of Scientific and Technical Information of China (English)

    YU Yi-fan; YIN Chang-chuan; YUE Guang-xin

    2005-01-01

    Recently, hosts of Medium Access Control (MAC) protocols for Ad hoc radio networks have been proposed to solve the hidden terminal problem and exposed terminal problem. However most of them take into no account the interactions between physical (PHY) system and MAC protocol. Therefore, the current MAC protocols are either inefficient in the networks with mobile nodes and fading channel or difficult in hardware implementation. In this paper, we present a novel media access control for Ad hoc networks that integrates a media access control protocol termed as Dual Busy Tone Multiple Access (DBTMA) into Orthogonal Frequency Division Multiplexing (OFDM) system proposed in IEEE 802.11a standard. The analysis presented in the paper indicates that the proposed MAC scheme achieves performance improvement over IEEE 802.11 protocol about 25%~80% especially in the environment with high mobility and deep fading. The complexity of the proposed scheme is also lower than other implementation of similar busy tone solution. Furthermore, it is compatible with IEEE 802.11a networks.

  9. Preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, C.L.; O' Rourke, J.E.; Allirot, D.; O' Connor, K.

    1980-09-01

    This report presents results of a study leading to preconceptual designs for plugging boreholes, shafts, and tunnels to a nuclear waste repository in basalt. Beginning design criteria include a list of preferred plug materials and plugging machines that were selected to suit the environmental conditions, and depths, diameters, and orientations of the accesses to a nuclear waste repository in the Columbia River basalts located in eastern Washington State. The environmental conditions are described. The fiscal year 1979-1980 Task II work is presented in two parts: preliminary testing of materials for plugging of man-made accesses to a repository in basalt (described in a separate report); and preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt (described in this report). To fulfill the scope of the Task II work, Woodward-Clyde Consultants (WCC) was requested to: provide preconceptual systems for plugging boreholes, tunnels, and shafts in basalt; describe preconceptual borehole plugging equipment for placing the selected materials in man-made accesses; utilize the quality assurance program, program plan and schedule, and work plans previously developed for Task II; and prepare a preliminary report.

  10. A Prospective Multi-Center Clinical Trial to Compare Efficiency, Accuracy and Safety Of the VisionScope Imaging System Compared to MRI and Diagnostic Arthroscopy

    Science.gov (United States)

    Xerogeanes, John W.; Safran, Marc R.; Huber, Bryan; Mandelbaum, Bert R.; Robertson, William; Gambardella, Ralph A.

    2014-01-01

    Objectives: Until now, arthroscopic surgery has been the gold standard for the diagnosis of intra-articular pathology. When a patient presents with ongoing pain and/or disability despite non-operative care, MRI is commonly used as a diagnostic modality. To date, there is not a minimally-invasive option that can provide detailed information about the intra-articular pathology of a joint. VisionScope Imaging (VSI) is an office-based diagnostic modality that provides comprehensive real-time images and video of a joint with higher accuracy and reliability compared to static MR images. The purpose of this study was to compare the efficacy, accuracy and safety of VSI compared to MRI and surgical diagnostic arthroscopy. Methods: A prospective, blinded, multi-centered study was performed of all patients who had a routine surgical arthroscopy at one of the six participating clinical sites between July 2012 and May 2013. Patients were consented by the physician investigator at each site. Study inclusion criteria consisted of: suspected meniscal tears or articular cartilage damage. Patients were excluded from the study if they had (1) acute traumatic hemarthoses, (2) concomitant ligament injury, (3) active systemic infection, (4) allergy to silicone or any medication used during the procedure,. All patients had a MRI and a comprehensive physical exam prior to their surgical arthroscopy. Each patient underwent a MRI, VSI exam and surgical diagnostic arthroscopy. The attending physician completed standard forms comparing the VSI exam findings to the diagnostic arthroscopy findings on each patient. Two blinded experts unaffiliated with the study reviewed the VSI and MRI images. The arthroscopy served as the “control” comparison between the VSI and MRI findings. Results: There were 110 patients included in this study. The accuracy, sensitivity and specificity of VSI was equivalent to surgical diagnostic arthroscopy and more accurate than MRI (Table 1). When comparing VSI to

  11. A study of usefulness for the plan based on only MRI using ViewRay MRIdian system

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Chang Woo; Lee, Ho Jin; An, Beom Seok; Kim, Chan Young; Lee, Je Hee [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2015-12-15

    By comparing a CT fusion plan based on MRI with a plan based on only MRI without CT, we intended to study usefulness of a plan based on only MRI. And furthermore, we intended to realize a realtime MR-IGRT by MRI image without CT scan during the course of simulation, treatment planning, and radiation treatment. BBB CT (Brilliance Big Bore CT, 16slice, Philips), Viewray MRIdian system (Viewray, USA) were used for CT and MR simulation and Treatment plan of 11 patients (1 Head and Neck, 5 Breast, 1 Lung, 3 Liver, 1 Prostate). When scanning for treatment, Free Breathing was enacted for Head and Neck, Breast, Prostate and Inhalation Breathing Holding for Lung and Liver. Considering the difference of size between CT and Viewray, the patient's position and devices were in the same condition. Using Viewray MRIdian system, two treatment plans were established. The one was CT fusion treatment plan based on MR image. Another was MR treatment plan including electron density that [ICRU 46] recommend for Lung, Air and Bone. For Head and Neck, Breast and Prostate, IMRT was established and for Lung and Liver, Gating treatment plan was established. PTV's Homogeneity Index(HI) and Conformity Index(CI) were use to estimate the treatment plan. And DVH and dose difference of each PTV and OAR were compared to estimate the treatment plan. Between the two treatment plan, each difference of PTV's HI value is 0.089% (Head and Neck), 0.26% (Breast), 0.67% (Lung), 0.2% (Liver), 0.4% (Prostate) and in case of CI, 0.043% (Head and Neck), 0.84% (Breast), 0.68% (Lung), 0.46% (Liver), 0.3% (Prostate). As showed above, it is on Head and Neck that HI and CI's difference value is smallest. Each difference of average dose on PTV is 0.07 Gy (Head and Neck), 0.29 Gy (Breast), 0.18 Gy (Lung), 0.3 Gy (Liver), 0.18 Gy (Prostate). And by percentage, it is 0.06% (Head and Neck), 0.7% (Breast), 0.29% (Lung), 0.69% (Liver), 0.44% (Prostate). Likewise, All is under 1%. In Head and Neck

  12. Conduction cooled magnet design for 1.5 T, 3.0 T and 7.0 T MRI systems

    International Nuclear Information System (INIS)

    Main magnets for magnetic resonance imaging (MRI) are largely constructed with low temperature superconducting material. Most commonly used superconductors for these magnets are niobium-titanium (NbTi). Such magnets are operated at 4.2 K by being immersed in a liquid helium bath for long time operation. As the cost of liquid helium has increased threefold in the last decade and the market for MRI systems is on average increasing by more than 7% every year, there is a growing demand for an alternative to liquid helium. Superconductors such as magnesium-diboride (MgB2) and niobium-tin (Nb3Sn) demonstrate superior current carrying quality at higher critical temperatures than 4.2 K. In this article, electromagnetic designs for conduction cooled main magnets over the range of medium field strengths (1.5 T) to ultrahigh field strengths (7.0 T) are presented. These designs are achieved by an improved functional approach coming from a series of developments by the present research group and using properties of the state-of-the-art second generation MgB2 wires and Nb3Sn wires developed by Hyper Tech Research Inc. The MgB2 magnet designs operated at different field strengths demonstrate excellent homogeneity and shielding properties at an operating temperature of 10 K. At ultrahigh field, the high current density on Nb3Sn allowed by the larger magnetic field on wire helps to reduce the superconductor volume in comparison with high field NbTi magnet designs. This allows for a compact magnet design that can operate at a temperature of 8 K. Overall, the designs created show promise in the development of conduction cooled dry magnets that would reduce dependence on helium. (paper)

  13. Case Study of Ecstatic Meditation: fMRI and EEG Evidence of Self-Stimulating a Reward System

    Directory of Open Access Journals (Sweden)

    Michael R. Hagerty

    2013-01-01

    Full Text Available We report the first neural recording during ecstatic meditations called jhanas and test whether a brain reward system plays a role in the joy reported. Jhanas are Altered States of Consciousness (ASC that imply major brain changes based on subjective reports: (1 external awareness dims, (2 internal verbalizations fade, (3 the sense of personal boundaries is altered, (4 attention is highly focused on the object of meditation, and (5 joy increases to high levels. The fMRI and EEG results from an experienced meditator show changes in brain activity in 11 regions shown to be associated with the subjective reports, and these changes occur promptly after jhana is entered. In particular, the extreme joy is associated not only with activation of cortical processes but also with activation of the nucleus accumbens (NAc in the dopamine/opioid reward system. We test three mechanisms by which the subject might stimulate his own reward system by external means and reject all three. Taken together, these results demonstrate an apparently novel method of self-stimulating a brain reward system using only internal mental processes in a highly trained subject.

  14. Welcome to Systems - A New Interdisciplinary Open Access Journal for Systems Science and Engineering

    OpenAIRE

    Huynh, Thomas

    2013-01-01

    The article of record as published may be found at http://dx.doi.org/10.3390/systems1010001 Natural and human-made systems abound around us. Our solar system, the human body, the food chain, and ecosystems are some examples of natural systems. Some human-made systems are transportation systems, weapon systems, computer systems, software systems, satellite communications systems, ships, missile defense systems, health care systems, the internet, financial systems, and regional economies.

  15. Face Recognition Based Door Lock System Using Opencv and C# with Remote Access and Security Features

    Directory of Open Access Journals (Sweden)

    Prathamesh Timse

    2014-04-01

    Full Text Available This paper investigates the accuracy and effectiveness of the face detection and recognition algorithms using OpenCV and C# computer language. The adaboost algorithm [2] is used for face detection and PCA algorithm[1] is used for face recognition. This paper also investigates the robustness of the face recognition system when an unknown person is being detected, wherein the system will send an email to the owner of the system using SMTP [7]. The door lock can also be accessed remotely from any part of the world by using a Dropbox [8] account.

  16. Urban air quality management and information systems in Europe: legal framework and information access

    International Nuclear Information System (INIS)

    The European Union (EU) legislative framework related to air quality, together with national legislation and relevant declarations of the United Nations (UN), requires an integrated approach concerning air quality management (AQM), and accessibility of related information for the citizens. In the present paper, the main requirements of this legislative framework are discussed and main air quality management and information system characteristics are drawn. The use of information technologies is recommended for the construction of such systems. The World Wide Web (WWW) is considered a suitable platform for system development and integration and at the same time as a medium for communication and information dissemination. (author)

  17. Security Camera System can be access into mobile with internet from remote place

    Directory of Open Access Journals (Sweden)

    Dr. Khanna SamratVivekanand Omprakash

    2012-01-01

    Full Text Available This paper represents how camera can captured the images and video into the database and then it may transformed to the mobile with help of Internet. Developing mobile applications how the data can be viewed on the mobile from the remote place. By assigning real IP to the storage device from ISP and connected to the internet . Developing mobile applications on windows mobile which runs only on the windows mobile . Wireless camera in terms of 4 , 8, 12, 16 are connected with the system. Windows based application develop for 4 , 8 , 12,16 channels to see at a time on desktop computer . The PC is connected with internet and having Client server application which is connected to the Windows Web hosting Server through the internet. With the help of ISP server we can assign IP to the Window Web Server with domain name . Domain name will be access from the world. By developing mobile applications on web we can access it on mobile . Separate setup of windows .exe develop for the Windows Mobile phone to access the information from the server. Client setup can be installed on the mobile and it fetches the data from server and server is based on real IP with domain name and connected with Internet . Digital Wireless cameras are connected & data is stored in Digital Video Recorder having 1 Terabyte of hard disk with different channel like 4, 8, 12,16. We can see Video output in mobile by installing the client setup or by accessing directly from web browser which supports the application for mobile. The beauty of this software is that we can access security camera system into the mobile with internet from remote place.

  18. S-band multiple-access interference study for advanced tracking and data relay satellite systems

    Science.gov (United States)

    Peng, Wei-Chung; Yang, Chau-Chin

    1990-01-01

    The results of a study on the effect of mutual interference among S-band multiple access (SMA) system users of advanced tracking and data relay satellite system (ATDRSS) are presented. In the ATDRSS era, the SMA system is required to support data rates ranging from 10 kb/s to 3 Mb/s. The system will consist of four advanced tracking and data relay satellites (ATDRS) each supporting up to five telemetry links. All users have 10 MHz bandwidth with their carrier frequency equal to 2.2875 GHz. A hybrid SDMA/CDMA scheme is used to mitigate the effect of the interference among system users. SMA system interference probability is evaluated with CLASS software. User link margin degradation due to mutual interference between two users is evaluated. System interference probability is evaluated for the projected 1996 mission model, a reference mission model, and a modified reference mission model.

  19. A fuzzy expert system to Trust-Based Access Control in crowdsourcing environments

    Directory of Open Access Journals (Sweden)

    Olusegun Folorunso

    2015-07-01

    Full Text Available Crowdsourcing has been widely accepted across a broad range of application areas. In crowdsourcing environments, the possibility of performing human computation is characterized with risks due to the openness of their web-based platforms where each crowd worker joins and participates in the process at any time, causing serious effect on the quality of its computation. In this paper, a combination of Trust-Based Access Control (TBAC strategy and fuzzy-expert systems was used to enhance the quality of human computation in crowdsourcing environment. A TBAC-fuzzy algorithm was developed and implemented using MATLAB 7.6.0 to compute trust value (Tvalue, priority value as evaluated by fuzzy inference system (FIS and finally generate access decision to each crowd-worker. In conclusion, the use of TBAC is feasible in improving quality of human computation in crowdsourcing environments.

  20. A METHOD OF AND A SYSTEM FOR CONTROLLING ACCESS TO A SHARED RESOURCE

    DEFF Research Database (Denmark)

    2006-01-01

    A method and a system of controlling access of data items to a shared resource, wherein the data items each is assigned to one of a plurality of priorities, and wherein, when a predetermined number of data items of a priority have been transmitted to the shared resource, that priority will be awa...... will be awaiting, i.e. no further data items are transmitted with that priority, until all lower, non-awaiting priorities have had one or more data items transmitted to the shared resource. In this manner, guarantees services may be obtained for all priorities.......A method and a system of controlling access of data items to a shared resource, wherein the data items each is assigned to one of a plurality of priorities, and wherein, when a predetermined number of data items of a priority have been transmitted to the shared resource, that priority...

  1. Design of a control system for self-shielded irradiators with remote access capability

    International Nuclear Information System (INIS)

    With self-shielded irradiators like Gamma chambers, and Blood irradiators are being sold by BRIT to customers both within and outside the country, it has become necessary to improve the quality of service without increasing the overheads. The recent advances in the field of communications and information technology can be exploited for improving the quality of service to the customers. A state of the art control system with remote accessibility has been designed for these irradiators enhancing their performance. This will provide an easy access to these units wherever they might be located, through the Internet. With this technology it will now be possible to attend to the needs of the customers, as regards fault rectification, error debugging, system software update, performance testing, data acquisition etc. This will not only reduce the downtime of these irradiators but also reduce the overheads. (author)

  2. Exploring the drivers of health and healthcare access in Zambian prisons: a health systems approach

    Science.gov (United States)

    Topp, Stephanie M.; Moonga, Clement N.; Luo, Nkandu; Kaingu, Michael; Chileshe, Chisela; Magwende, George; Heymann, S. Jody; Henostroza, German

    2016-01-01

    Background Prison populations in sub-Saharan Africa (SSA) experience a high burden of disease and poor access to health care. Although it is generally understood that environmental conditions are dire and contribute to disease spread, evidence of how environmental conditions interact with facility-level social and institutional factors is lacking. This study aimed to unpack the nature of interactions and their influence on health and healthcare access in the Zambian prison setting. Methods We conducted in-depth interviews of a clustered random sample of 79 male prisoners across four prisons, as well as 32 prison officers, policy makers and health care workers. Largely inductive thematic analysis was guided by the concepts of dynamic interaction and emergent behaviour, drawn from the theory of complex adaptive systems. Results A majority of inmates, as well as facility-based officers reported anxiety linked to overcrowding, sanitation, infectious disease transmission, nutrition and coercion. Due in part to differential wealth of inmates and their support networks on entering prison, and in part to the accumulation of authority and material wealth within prison, we found enormous inequity in the standard of living among prisoners at each site. In the context of such inequities, failure of the Zambian prison system to provide basic necessities (including adequate and appropriate forms of nutrition, or access to quality health care) contributed to high rates of inmate-led and officer-led coercion with direct implications for health and access to healthcare. Conclusions This systems-oriented analysis provides a more comprehensive picture of the way resource shortages and human interactions within Zambian prisons interact and affect inmate and officer health. While not a panacea, our findings highlight some strategic entry-points for important upstream and downstream reforms including urgent improvement in the availability of human resources for health; strengthening of

  3. An Acquisition Performance Analysis of DS-MC-CDMA System under Multiple Access Interference Conditions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Multi-Access Interference's (MAI's) effect on parallel acquisition performance of DS-Multi-carrier CDMA system under the typical indoor radio channel is discussed in the paper. Moreover, a comparison of acquisition performance impairment produced by the MAI in DS-MC-CDMA and DS-Single-carrier CDMA is also made. Results are given in terms of average acquisition time obtained by means of simulations and theory analysis.

  4. A fuzzy expert system to Trust-Based Access Control in crowdsourcing environments

    OpenAIRE

    Olusegun Folorunso; Olusegun Afeez Mustapha

    2015-01-01

    Crowdsourcing has been widely accepted across a broad range of application areas. In crowdsourcing environments, the possibility of performing human computation is characterized with risks due to the openness of their web-based platforms where each crowd worker joins and participates in the process at any time, causing serious effect on the quality of its computation. In this paper, a combination of Trust-Based Access Control (TBAC) strategy and fuzzy-expert systems was used to enhance the qu...

  5. Multiagent Q-Learning for Aloha-Like Spectrum Access in Cognitive Radio Systems

    OpenAIRE

    Husheng Li

    2010-01-01

    An Aloha-like spectrum access scheme without negotiation is considered for multiuser and multichannel cognitive radio systems. To avoid collisions incurred by the lack of coordination, each secondary user learns how to select channels according to its experience. Multiagent reinforcement leaning (MARL) is applied for the secondary users to learn good strategies of channel selection. Specifically, the framework of Q-learning is extended from single user case to multiagent case by considering o...

  6. Evaluation and Improvement of Web Information System Accessibility with Markup Language Possibilities

    OpenAIRE

    Vitols, G; Arhipova, I

    2010-01-01

    Markup languages are used to describe the content published in the World Wide Web. Aim of this article is to analyze hypertext markup language versions and identify possibilities of improvement accessibility for the web information systems with markup language elements appropriate application. Analysis of the document structure is performed. Document structure and text description elements are selected. Selected elements are practically evaluated with screen readers. From the evaluation resul...

  7. A High-Throughput Random Access Protocol for Multiuser MIMO Systems

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2008-05-01

    Full Text Available We propose a high-throughput random access protocol for 2×2 multiuser multiple-input multiple-output (MIMO systems. The cross-layer mechanism utilizes the packets combining technique to exploit the advantages of both spatial multiplexing and multipacket reception. Analytical result indicates that the proposed scheme achieves 0.669 per spatial degree of freedom in stable throughput, which is much higher than those in the existed studies.

  8. Design of Nutrition Catering System for Athletes Based on Access Database

    OpenAIRE

    Hongjiang Wu,; Haiyan Zhao; Xugang Liu; Mingshun Xing

    2015-01-01

    In order to monitor and adjust athletes' dietary nutrition scientifically, Active X Data Object (ADO) and Structure Query Language (SQL) were used to produce program under the development environment of Visual Basic 6.0 and Access database. The consulting system on food nutrition and dietary had been developed with the two languages combination and organization of the latest nutrition information. Nutrition balance of physiological characteristics, assessment for nutrition intake, inquiring n...

  9. Battlefield MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-01

    Magnetic Resonance Imaging is the best method for non-invasive imaging of soft tissue anatomy, saving countless lives each year. It is regarded as the gold standard for diagnosis of mild to moderate traumatic brain injuries. Furthermore, conventional MRI relies on very high, fixed strength magnetic fields (> 1.5 T) with parts-per-million homogeneity, which requires very large and expensive magnets.

  10. Access To Land And The System Of Land Ownership In Northern Cameroon

    Directory of Open Access Journals (Sweden)

    Paul AHIDJO

    2012-06-01

    Full Text Available Northern Cameroon is a vast geographical region made up of a population with diverse customs, religion and migration process. The entire population is made up of paleo-nigritics, neo-Sudanese and pastoral nomads who practice activities such as agriculture, livestock and fisheries. This ethnic heterogeneity, complex historical events and cultural diversity has made the customary systemof land tenure to vary both in their ancient aspects as well as contemporary manifestations. Therefore, based on verbal assertion and written data, this article examines the methods of land access as well as the traditional and modern land tenure system. For the population of Northern Cameroon and elsewhere, land represents a natural resource of prime importance. Access to land and its control constitutes a major economic challenge and it is equally a source ofdiverse conflicts. The system of land ownership has been influenced by external unforeseen events. From the pre-colonial period to the so called post colonial period, access to land and land ownership vary between the conservation of a traditional system which land owners are trying to preserve and the weight of modernity which has economic implications.

  11. New capabilities in the HENP grand challenge storage access system and its application at RHIC

    International Nuclear Information System (INIS)

    The High Energy and Nuclear Physics Data Access Grand Challenge project has developed an optimizing storage access software system that was prototyped at RHIC. It is currently undergoing integration with the STAR experiment in preparation for data taking that starts in mid-2000. The behavior and lessons learned in the RHIC Mock Data Challenge exercises are described as well as the observed performance under conditions designed to characterize scalability. Up to 250 simultaneous queries were tested and up to 10 million events across 7 event components were involved in these queries. The system coordinates the staging of ''bundles'' of files from the HPSS tape system, so that all the needed components of each event are in disk cache when accessed by the application software. The caching policy algorithm for the coordinated bundle staging is described in the paper. The initial prototype implementation interfaced to the Objectivity/DB. In this latest version, it evolved to work with arbitrary files and use CORBA interfaces to the tag database and file catalog services. The interface to the tag database and the MySQL-based file catalog services used by STAR are described along with the planned usage scenarios

  12. A practical MRI grading system for osteoarthritis of the knee: Association with Kellgren–Lawrence radiographic scores

    International Nuclear Information System (INIS)

    Purpose: To propose a reproducible and constant MR grading system for osteoarthritis of the knee joint that provides high interobserver and intraoberver agreement and that does not require complicated calculation procedures. Materials and methods: This retrospective study sample included 44 men and 65 women who underwent both MRI and plain radiography of the knee at our institution. All patients were older than 50 years of age (mean 57.7) and had clinically suspected osteoarthritis of the knee. The standard of 4 grades on the MR grade scale was based mainly on cartilage injury and additional findings. Kellgren–Lawrence grades were assessed for the same patient group. The relationship between the results was determined. Statistical analyses were performed including kappa statistics, categorical regression analysis and nonparametric correlation analysis. Results: The interobserver and intraoberver agreements between the two readers in the grading of osteoarthritis were found to be almost perfect. Interobserver and intraobserver agreements were slightly lower for the MR grading system than for the Kellgren–Lawrence grading scale. The correlation between the MR grade and Kellgren–Lawrence grade was very high and did not differ with patient age. The MR grades were highly correlated with the Kellgren–Lawrence grades and showed excellent interobserver and intraobserver agreements. Conclusion: This new MR grading system for osteoarthritis of the knee joint is reproducible and may be helpful for the grading of osteoarthritis of the knee without requiring reference to plain radiography

  13. A practical MRI grading system for osteoarthritis of the knee: Association with Kellgren–Lawrence radiographic scores

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hee-Jin, E-mail: parkhiji@gmail.com [Department of Radiology, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, #108 Pyung-dong, Jongno-gu, Seoul 110-746 (Korea, Republic of); Department of Radiology, Kangwon National University School of Medicine, Baengnyeong-ro 156, Chuncheon-Si, Gangwon-Do Kangwon National University Hospital 200-722 (Korea, Republic of); Kim, Sam Soo, E-mail: samskim@kangwon.ac.kr [Department of Radiology, Kangwon National University School of Medicine, Baengnyeong-ro 156, Chuncheon-Si, Gangwon-Do Kangwon National University Hospital 200-722 (Korea, Republic of); Lee, So-Yeon, E-mail: parkhiji@kwandong.ac.kr [Department of Radiology, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, #108 Pyung-dong, Jongno-gu, Seoul 110-746 (Korea, Republic of); Park, Noh-Hyuck, E-mail: nhpark904@kwandong.ac.kr [Department of Radiology, Myongji Hospital, Kwandong University, College of Medicine, 697-24 Hwajung-dong, Dukyang-ku, Koyang, Kyunggi 412-270 (Korea, Republic of); Park, Ji-Yeon, E-mail: zzzz3@hanmail.net [Department of Radiology, Myongji Hospital, Kwandong University, College of Medicine, 697-24 Hwajung-dong, Dukyang-ku, Koyang, Kyunggi 412-270 (Korea, Republic of); Choi, Yoon-Jung, E-mail: yoonchoi99@gmail.com [Department of Radiology, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, #108 Pyung-dong, Jongno-gu, Seoul 110-746 (Korea, Republic of); Jeon, Hyun-Jun, E-mail: ostrich-13@hanmail.net [Department of Occupational Medicine, Dongsan Medical Center, Keimyung University School of Medicine, 194 Dongsan-Dong, Jung-ku, Taegu (Korea, Republic of)

    2013-01-15

    Purpose: To propose a reproducible and constant MR grading system for osteoarthritis of the knee joint that provides high interobserver and intraoberver agreement and that does not require complicated calculation procedures. Materials and methods: This retrospective study sample included 44 men and 65 women who underwent both MRI and plain radiography of the knee at our institution. All patients were older than 50 years of age (mean 57.7) and had clinically suspected osteoarthritis of the knee. The standard of 4 grades on the MR grade scale was based mainly on cartilage injury and additional findings. Kellgren–Lawrence grades were assessed for the same patient group. The relationship between the results was determined. Statistical analyses were performed including kappa statistics, categorical regression analysis and nonparametric correlation analysis. Results: The interobserver and intraoberver agreements between the two readers in the grading of osteoarthritis were found to be almost perfect. Interobserver and intraobserver agreements were slightly lower for the MR grading system than for the Kellgren–Lawrence grading scale. The correlation between the MR grade and Kellgren–Lawrence grade was very high and did not differ with patient age. The MR grades were highly correlated with the Kellgren–Lawrence grades and showed excellent interobserver and intraobserver agreements. Conclusion: This new MR grading system for osteoarthritis of the knee joint is reproducible and may be helpful for the grading of osteoarthritis of the knee without requiring reference to plain radiography.

  14. Neural Response during the Activation of the Attachment System in Patients with Borderline Personality Disorder: An fMRI Study

    Science.gov (United States)

    Buchheim, Anna; Erk, Susanne; George, Carol; Kächele, Horst; Martius, Philipp; Pokorny, Dan; Spitzer, Manfred; Walter, Henrik

    2016-01-01

    Individuals with borderline personality disorder (BPD) are characterized by emotional instability, impaired emotion regulation and unresolved attachment patterns associated with abusive childhood experiences. We investigated the neural response during the activation of the attachment system in BPD patients compared to healthy controls using functional magnetic resonance imaging (fMRI). Eleven female patients with BPD without posttraumatic stress disorder (PTSD) and 17 healthy female controls matched for age and education were telling stories in the scanner in response to the Adult Attachment Projective Picture System (AAP), an eight-picture set assessment of adult attachment. The picture set includes theoretically-derived attachment scenes, such as separation, death, threat and potential abuse. The picture presentation order is designed to gradually increase the activation of the attachment system. Each picture stimulus was presented for 2 min. Analyses examine group differences in attachment classifications and neural activation patterns over the course of the task. Unresolved attachment was associated with increasing amygdala activation over the course of the attachment task in patients as well as controls. Unresolved controls, but not patients, showed activation in the right dorsolateral prefrontal cortex (DLPFC) and the rostral cingulate zone (RCZ). We interpret this as a neural signature of BPD patients’ inability to exert top-down control under conditions of attachment distress. These findings point to possible neural mechanisms for underlying affective dysregulation in BPD in the context of attachment trauma and fear. PMID:27531977

  15. Access Denied

    Science.gov (United States)

    Villano, Matt

    2008-01-01

    Building access control (BAC)--a catchall phrase to describe the systems that control access to facilities across campus--has traditionally been handled with remarkably low-tech solutions: (1) manual locks; (2) electronic locks; and (3) ID cards with magnetic strips. Recent improvements have included smart cards and keyless solutions that make use…

  16. Distributed Multi-Sensor Real-Time Building Environmental Parameters Monitoring System with Remote Data Access

    Directory of Open Access Journals (Sweden)

    Beinarts Ivars

    2014-12-01

    Full Text Available In this paper the advanced monitoring system of multiple environmental parameters is presented. The purpose of the system is a long-term estimation of energy efficiency and sustainability for the research test stands which are made of different building materials. Construction of test stands, and placement of main sensors are presented in the first chapter. The structure of data acquisition system includes a real-time interface with sensors and a data logger that allows to acquire and log data from all sensors with fixed rate. The data logging system provides a remote access to the processing of the acquired data and carries out periodical saving at a remote FTP server using an Internet connection. The system architecture and the usage of sensors are explained in the second chapter. In the third chapter implementation of the system, different interfaces of sensors and energy measuring devices are discussed and several examples of data logger program are presented. Each data logger is reading data from analog and digital channels. Measurements can be displayed directly on a screen using WEB access or using data from FTP server. Measurements and acquired data graphical results are presented in the fourth chapter in the selected diagrams. The benefits of the developed system are presented in the conclusion.

  17. Global system data bus using the Digital Autonomous Terminal Access Communication protocol

    Science.gov (United States)

    Holmes, David C. E.

    1986-01-01

    Modern digital avionic systems with distributed processing require networking to connect the many elements. Digital Autonomous Terminal Access Communication (DATAC) is one of many such networks. DATAC has been implemented on the Transport Systems Research Vehicle (TSRV), a Boeing 737 aircraft operated by the National Aeronautics and Space Administration's Advanced Transport Operating Systems Program Office (ATOPS). This paper presents the TSRV implementation of the DATAC bus, a description of the DATAC system, a synchronization mechanism, details of data flow throughout the system, and a discussion of the modes available with DATAC. Numerous flight tests have been conducted using DATAC as the only means of communication between systems with outstanding results. DATAC is now an integral part of the TSRV and is expected to satisfy near term as well as future requirements for growth and flexibility.

  18. Smart Bank Locker Access System Using Iris ,Fingerprints,Face Recognization Along With Password Authentication And Billing System

    Directory of Open Access Journals (Sweden)

    Asst.Prof.T.A.More

    2015-03-01

    Full Text Available In today's modern world, security plays an important role. For that purpose, we proposed advance security systems for banking locker system and the bank customers. This specialized security is proposed through four different modules in combination i.e. face detection technique, Password verification, finger prints and Iris verification .All these steps are followed in the sequence if anything goes wrong he or she is unable to access the system. We are also providing some additional billing with it i.e. it will always for after 1 transaction. It will give the intimation of first transaction is complete and you are left with prescribed number transaction mentioned in system.

  19. The optimal access system for future far-offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Obdam, T.S.; Rademakers, L.W.M.M.; Savenije, L.B. [ECN Wind Energy, Petten (Netherlands)

    2013-12-15

    Operation and maintenance (O and M) of offshore wind turbines is one of the main cost drivers of offshore wind energy. One of the aspects critical for an efficient and cost-effective O and M strategy is the selection of the access system which is used to transfer technicians and, optionally, small spare parts. Currently, most offshore wind farms are located close to shore, and their size is relatively small. For these farms the typical access system consists of catamaran-like workboats, which are used to transfer both technicians and small spare parts. As wind farms move further offshore this O and M concept might no longer be cost-effective. Currently, different alternative O and M concepts are being considered for the future far-offshore sites. In this paper an extensive and holistic comparison of different O and M concepts including different access system solutions is presented. This analysis has been performed using the OMCECalculator, ECN's software for advanced O and M cost modelling. Different sites have been considered, which are typical for the future offshore wind farms that will be commissioned during the next five years. The results of the performed analyses indicate that when moving further offshore harbour-based O and M strategies are no longer economical, even when helicopters are added to the mix. Looking at farm-based O and M concepts a supply vessel with a compensated access gangway offers great potential. However, the calculations also indicate that its ability to transfer small spare parts, in addition to technicians, is crucial.

  20. Experimental demonstration of 2.5 Gbit/S incoherent two-dimensional optical code division multiple access system

    International Nuclear Information System (INIS)

    We demonstrated error-free operation of 4 simultaneous users in a fast frequency-hopping time-spreading optical code division multiple access system operating at 2.5 Gbit/s a Star architecture. Effective power penalty was ≤0.5dB. Novel optical code division multiple access receiver based on Terahertz Optical Asymmetric Demultiplexer was demonstrated to eliminate multiple access interference (Authors)

  1. Development of Remote Monitoring and a Control System Based on PLC and WebAccess for Learning Mechatronics

    OpenAIRE

    Wen-Jye Shyr; Te-Jen Su; Chia-Ming Lin

    2013-01-01

    This study develops a novel method for learning mechatronics using remote monitoring and control, based on a programmable logic controller (PLC) and WebAccess. A mechatronics module, a Web‐CAM and a PLC were integrated with WebAccess software to organize a remote laboratory. The proposed system enables users to access the Internet for remote monitoring and control of the mechatronics module via a web browser, thereby enhancing work flexibility by enabling personnel to control mechatronics equ...

  2. ACCESS TO A COMPUTER SYSTEM. BETWEEN LEGAL PROVISIONS AND TECHNICAL REALITY

    OpenAIRE

    Maxim DOBRINOIU

    2016-01-01

    Nowadays, on a rise of cybersecurity incidents and a very complex IT&C environment, the national legal systems must adapt in order to properly address the new and modern forms of criminality in cyberspace. The illegal access to a computer system remains one of the most important cyber-related crimes due to its popularity but also from the perspective as being a door opened to computer data and sometimes a vehicle for other tech crimes. In the same time, the information society services slight...

  3. Adaptive radio resource allocation for multiple traffic OFDMA broadband wireless access system

    Institute of Scientific and Technical Information of China (English)

    LU Yan-hui; LUO Tao; YIN Chang-chuan; YUE Guang-xin

    2006-01-01

    In this article, an adaptive radio resource allocation algorithm applied to multiple traffic orthogonal frequency division multiple access (OFDMA) system is proposed, which distributes subcarriers and bits among users according to their different quality of service requirements and traffic type. By classifying and prioritizing the users based on their traffic characteristic and ensuring resource for higher priority users, the new scheme decreases tremendously the outage probability of the users requiting a real-time transmission without impact on the spectrum efficiency of system, as well as the outage probability of data users is not increased compared with the radio resource allocation methods published.

  4. The FODA-TDMA satellite access scheme - Presentation, study of the system, and results

    Science.gov (United States)

    Celandroni, Nedo; Ferro, Erina

    1991-12-01

    A description is given of FODA-TDMA, a satellite access scheme designed for mixed traffic. The study of the system is presented and the choice of some parameters is justified. A simplified analytic solution is found, describing the steady-state behavior of the system. Some results of the simulation tests for an already existing hardware environment are also presented for the channel speeds of 2 and 8 Mb/s, considering both the stationary and the transient cases. The results of the experimentation at 2 Mb/s on the satellite Eutelsat-F2 are also presented and compared with the results of the simulation.

  5. Using geographic information system tools to improve access to MS specialty care in Veterans Health Administration

    Directory of Open Access Journals (Sweden)

    William J. Culpepper, II, PhD, MA

    2010-08-01

    Full Text Available Access to appropriate and timely healthcare is critical to the overall health and well-being of patients with chronic diseases. In this study, we used geographic information system (GIS tools to map Veterans Health Administration (VHA patients with multiple sclerosis (MS and their access to MS specialty care. We created six travel-time bands around VHA facilities with MS specialty care and calculated the number of VHA patients with MS who resided in each time band and the number of patients who lived more than 2 hours from the nearest specialty clinic in fiscal year 2007. We demonstrate the utility of using GIS tools in decision-making by providing three examples of how patients' access to care is affected when additional specialty clinics are added. The mapping technique used in this study provides a powerful and valuable tool for policy and planning personnel who are evaluating how to address underserved populations and areas within the VHA healthcare system.

  6. Towards the Adoption of Open Source and Open Access Electronic Health Record Systems

    Directory of Open Access Journals (Sweden)

    Ilias Maglogiannis

    2012-01-01

    Full Text Available As the Electronic Health Record (EHR systems constantly expand to support more clinical activities and their implementations in healthcare organizations become more widespread, several communities have been working intensively for several years to develop open access and open source EHR software, aiming at reducing the costs of EHR deployment and maintenance. In this paper, we describe and evaluate the most popular open source electronic medical records such as openEMR, openMRS and patientOS, providing their technical features and potentials. These systems are considered quite important due to their prevalence. The article presents the key features of each system and outlines the advantages and problems of Open Source Software (OSS Systems through a review of the literature, in order to demonstrate the possibility of their adoption in modern electronic healthcare systems. Also discussed are the future trends of OS EHRs in the context of the Personal Health Records and mobile computing paradigm.

  7. Low Access Delay Anti-Collision Algorithm for Reader in RFID systems

    DEFF Research Database (Denmark)

    Galiotto, Carlo; Marchetti, Nicola; Prasad, Neeli R.;

    2010-01-01

    Radio Frequency Identification (RFID) is a technology which is spreading more and more as a medium to identify, locate and track assets through the productive chain. As all the wireless communication devices sharing the same transmission channel, RFID readers and tags experience collisions whenever...... deployed over the same area. In this work, the RFID reader collision problem is studied and a centralized scheduling-based algorithm is proposed as possible candidate solution, especially for those scenarios involving static or low mobility readers. Taking into account the circuitry limitations of the tags......, which do not allow to use frequency or code division multiple access schemes in the RFID systems, this paper proposes an algorithm aiming to prevent the readers collisions, while keeping the access delay of the readers to the channel possibly low. The simulation results show that this algorithm performs...

  8. Reduce Threats in Competitive Intelligence System: A Generic Information Fusion Access Control Model

    Directory of Open Access Journals (Sweden)

    Anass El haddadi

    2011-03-01

    Full Text Available Information fusion is a cornerstone of competitive intelligence activity that aims at supporting decisionmaking by collecting, analyzing and disseminating information. This information comes fromheterogeneous data sources. In this paper we present an approach of access control. This approach isfocused both on the information that must be bring to decision-makers and the privacy of individuals whosedata is used to extract this information. This model is based on the standard “Role Based Access Control”(RBAC and is implemented within the entire life cycle of Xplor Every Where (Web service of Tetralogie,it follows methodologies tailored to design privacy-aware systems to be compliant with data protectionregulations.

  9. ICIS 2008 panel report: open access publishing to nurture the sprouts of knowledge and the future of information systems research

    NARCIS (Netherlands)

    M. Avital; B-C. Björk; R.J. Boland; K. Crowston; K. Lyytinen; A. Majchrzak

    2009-01-01

    The advent of the Internet and the subsequent adoption of Open Access schemata are changing the nature of the scholarly discourse. In response, we seek to stimulate a debate about the role and desired forms of Open Access publishing in the context of the Information System (IS) discipline. We explor

  10. What Is Chest MRI?

    Science.gov (United States)

    ... from the NHLBI on Twitter. What Is Chest MRI? Chest MRI (magnetic resonance imaging) is a safe, noninvasive test. "Noninvasive" means that ... your chest wall, heart, and blood vessels. Chest MRI uses radio waves, magnets, and a computer to ...

  11. Breast MRI scan

    Science.gov (United States)

    MRI - breast; Magnetic resonance imaging - breast; Breast cancer - MRI; Breast cancer screening - MRI ... your stomach on a narrow table with your breasts hanging down into cushioned openings. The table slides ...

  12. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options ... 8 MB) Also available in Other Language versions . Magnetic Resonance Imaging (MRI) is a medical imaging procedure for making ...

  13. Wireless Accelerometer for MRI-Guided Interventional Procedures

    Directory of Open Access Journals (Sweden)

    Martyn N.J. Paley

    2013-12-01

    Full Text Available MRI-guidance is increasingly used for minimally-invasive procedures, such as biopsy, and requires real-time active tracking of surgical instruments. Although optical and MR-based fiducial tracking devices have been used, these systems rely on complex contact with the operator or line-of-sight access for effective operation. A more straight-forward and clinically robust method is required to allow interactive real-time slice positioning of MR scan planes during interventional procedures. This study evaluated the use of a wristwatch-mounted, low cost wireless interface device for real-time MRI guidance. The device was designed to interact with software for planning rather than instrument guidance. The wireless device was integrated with two novel, open interventional magnet systems operating at 0.17T and 0.5T and utilized a novel customized graphic user interface (GUI to assess interventional capability.

  14. Performance analysis on data access patterns in layered Information Systems, an Architectural Perspective

    Directory of Open Access Journals (Sweden)

    Gholamali Nejad Hajali Irani

    2012-05-01

    Full Text Available Layered architectures are the main architectures that are used in architecture of Information Systems. Data Access Layer (DAL is a common layer in all layered architecture of Information Systems. One of the most important steps in architectural design of information systems is designing the DAL. More than 20 Data Access Patterns (DAP have been developed for DALs. So providing a DAL based on existing DAPs is major activity in architectural design. Therefore an architect should be familiar to all existing DAPs and their evaluation parameters. Performance is one of most important parameter in architecture evaluation. In this paper, different aspects of performance of existing DAPs have been investigated and analyzed. To obtain this aim, firstly, a new classification has been provided for categorizing all DAPs based on architectures difference of them. Secondly, a simulation program as named DALSim has been developed for measuring performance of all DAPs. Finally, some comparisons of DAPs have been provided based on DALSim results. Based on provided classification for DAPs and performance comparison results of them, architects of information systems can easily compare and evaluate existing DAPs. With fully development of provided results in other aspect such as modifiability, extensibility, security etc., a complete framework for all DAPs can be provided.

  15. Wideband Wireless Access Systems Interference Robustness: Its Effect on Quality of Video Streaming

    Directory of Open Access Journals (Sweden)

    Aderemi A. Atayero

    2012-01-01

    Full Text Available A necessary requirement incumbent on any information communication system and/or network is the capacity to transmit information with a predefined degree of accuracy in the presence of inevitable interference. The transmission of audio and video streaming services over different conduits (wireless access systems, Internet, etc. is becoming ever more popular. As should be expected, this widespread increase is accompanied by the attendant new and difficult task of maintaining the quality of service of streaming video. The use of very accurate coding techniques for transmissions over wireless networks alone cannot guarantee a complete eradication of distortions characteristic of the video signal. A software-hardware composite system has been developed for investigating the effect of single bit error and bit packet errors in wideband wireless access systems on the quality of H.264/AVC standard bursty video streams. Numerical results of the modeling and analysis of the effect of interference robustness on quality of video streaming are presented and discussed.

  16. A Frequency—Diversity Spread—Spectrum Multiple Access System with Random Signature Sequences

    Institute of Scientific and Technical Information of China (English)

    CaoYewen; XiangHaige

    1995-01-01

    A new scheme for the spread-spectrum multiple access system named Frequency-Diver-sity Spread-Spectrum Multiple Access(FD-DDMA)system,is proposed.In this FD-SSMA sys-tem,the same information will be modulated on a group of mutually orthogonal frequency compo-nents(carriers)with a random signature sequence at the same time,and it will be demodulated by a coherent receiver for every component and then incorporated (ad if using frequency diversity)on the basis of this random sequence.The spectrum of the modulated signal is very close to that of a white-noise in a wider frequency band due to orthogonality for all frequency components and prop-erty of the random sequence,the system becomes a spread-spectrum one.The (Inverse)Fast Froier Transform(IFFT,FFT)can be applied in the system ,which provides additional flexibility.The performance in an asynchronous mode,such as ability of multiusers,anti-interferences ,is an-alyzed.

  17. A new MRI-compatible optical fiber tactile sensor for use in minimally invasive robotic surgery systems

    Science.gov (United States)

    Ahmadi, Roozbeh; Dargahi, Javad; Packirisamy, Muthukumaran; Cecere, Renzo

    2010-09-01

    In conventional open surgery, using finger palpation, surgeons can distinguish between different types of tissues. However, in the current commercially available minimally invasive robotic surgery (MIRS) systems, direct tactile feedback is negligible. In the present paper, based on a novel concept, a new bend-type optical fiber tactile sensor is proposed, designed, simulated, fabricated, and tested. In both dynamic and static loading conditions, the proposed tactile sensor measures forces interacting between tissues and surgical tools whether they are distributed contact forces or concentrated contact forces, or even if these forces are in combination. As a result, the sensor can identify the size and the position of blood vessels or of abnormal tissues, one of which could be a tumorous lump within normal tissues. In addition, the static force measurement provided by the sensor allows surgeons to maintain contact stability in any static interactions between surgical tools and tissues while at the same time avoiding tissue damage because of excessive contact force. In the meantime, because the sensor is based uniquely on optical fibers, it is insensitive to electromagnetic fields. As a result, it is compatible with Magnetic Resonance Imaging (MRI) devices, which are currently in widespread use in surgical operating rooms.

  18. A Hybrid System for the Semantic Annotation of Sulco-Gyral Anatomy in MRI Images.

    OpenAIRE

    Mechouche, Ammar; Morandi, Xavier; Golbreich, Christine; Gibaud, Bernard

    2008-01-01

    This paper presents an interactive system for the annotation of brain anatomical structures in Magnetic Resonance Images. The system is based on hybrid knowledge and techniques. First, it exploits both numerical knowledge from atlases and symbolic knowledge from a ruleextended ontology represented in OWL, the Web ontology language, and combines them with graphical data about cortical sulci, automatically extracted from the images. Second, the annotations of the parts of gyri and of sulci loca...

  19. Accessibility patterns and community integration among previously homeless adults: a Geographic Information Systems (GIS) approach.

    Science.gov (United States)

    Chan, Dara V; Gopal, Sucharita; Helfrich, Christine A

    2014-11-01

    Although a desired rehabilitation goal, research continues to document that community integration significantly lags behind housing stability success rates for people of a variety of ages who used to be homeless. While accessibility to resources is an environmental factor that may promote or impede integration activity, there has been little empirical investigation into the impact of proximity of community features on resource use and integration. Using a Geographic Information Systems (GIS) approach, the current study examines how accessibility or proximity to community features in Boston, United States related to the types of locations used and the size of an individual's "activity space," or spatial presence in the community. Significant findings include an inverse relationship between activity space size and proximity to the number and type of community features in one's immediate area. Specifically, larger activity spaces were associated with neighborhoods with less community features, and smaller activity spaces corresponded with greater availability of resources within one's immediate area. Activity space size also varied, however, based on proximity to different types of resources, namely transportation and health care. Greater community function, or the ability to navigate and use community resources, was associated with better accessibility and feeling part of the community. Finally, proximity to a greater number of individual identified preferred community features was associated with better social integration. The current study suggests the ongoing challenges of successful integration may vary not just based on accessibility to, but relative importance of, specific community features and affinity with one's surroundings. Community integration researchers and housing providers may need to attend to the meaning attached to resources, not just presence or use in the community.

  20. National Geothermal Data System (USA): an Exemplar of Open Access to Data

    Science.gov (United States)

    Allison, M. Lee; Richard, Stephen; Blackman, Harold; Anderson, Arlene; Patten, Kim

    2014-05-01

    The National Geothermal Data System's (NGDS - www.geothermaldata.org) formal launch in April, 2014 will provide open access to millions of data records, sharing -relevant geoscience and longer term to land use data to propel geothermal development and production. NGDS serves information from all of the U.S. Department of Energy's sponsored development and research projects and geologic data from all 50 states, using free and open source software. This interactive online system is opening new exploration opportunities and potentially shortening project development by making data easily discoverable, accessible, and interoperable. We continue to populate our prototype functional data system with multiple data nodes and nationwide data online and available to the public. Data from state geological surveys and partners includes more than 6 million records online, including 1.72 million well headers (oil and gas, water, geothermal), 670,000 well logs, and 497,000 borehole temperatures and is growing rapidly. There are over 312 interoperable Web services and another 106 WMS (Web Map Services) registered in the system as of January, 2014. Companion projects run by Southern Methodist University and U.S. Geological Survey (USGS) are adding millions of additional data records. The DOE Geothermal Data Repository, currently hosted on OpenEI, is a system node and clearinghouse for data from hundreds of U.S. DOE-funded geothermal projects. NGDS is built on the US Geoscience Information Network (USGIN) data integration framework, which is a joint undertaking of the USGS and the Association of American State Geologists (AASG). NGDS complies with the White House Executive Order of May 2013, requiring all federal agencies to make their data holdings publicly accessible online in open source, interoperable formats with common core and extensible metadata. The National Geothermal Data System is being designed, built, deployed, and populated primarily with support from the US

  1. Sub-THz photonic frequency conversion using optoelectronic transistors for future fully coherent access network systems

    Science.gov (United States)

    Otsuji, Taiichi; Sugawara, Kenta; Tamamushi, Gen; Dobroiu, Adrian; Suemitsu, Tetsuya; Ryzhii, Victor; Iwatsuki, Katsumi; Kuwano, Shigeru; Kani, Jun-ichi; Terada, Jun

    2016-02-01

    This paper reviews advances in sub-THz photonic frequency conversion using optoelectronic transistors for future fully coherent access network systems. Graphene-channel field effect transistors (G-FETs) and InP-based high electron mobility transistors (inP-HEMT) are experimentally examined as photonic frequency converters. Optoelectronic properties and three-terminal functionalities of the G-FETs and InP-HEMTs are exploited to perform single-chip photonic double-mixing operation over the 120 GHz wireless communication band. A single transistor can photomix the optical subcarriers to generate LO and mix down the RF data on the sub-THz carrier to the IF band.

  2. Measuring access to primary medical care: some examples of the use of geographical information systems.

    Science.gov (United States)

    Parker, E B; Campbell, J L

    1998-06-01

    This paper explores the potential for geographical information system technology in defining some variables influencing the use of primary care medical services. Eighteen general practices in Scotland contributed to a study examining the accessibility of their services and their patients' use of the local Accident and Emergency Department. Geo-referencing of information was carried out through analysis of postcode data relating to practices and patients. This information was analyzed using ARC/INFO GIS software in conjunction with the ORACLE relational database and 1991 census information. The results demonstrate that GIS technology has an important role in defining and analyzing the use of health services by the population. PMID:10671022

  3. The integration of open access journals in the scholarly communication system: Three science fields

    DEFF Research Database (Denmark)

    Faber Frandsen, Tove

    2009-01-01

    The greatest number of open access journals (OAJs) is found in the sciences and their influence is growing. However, there are only a few studies on the acceptance and thereby integration of these OAJs in the scholarly communication system. Even fewer studies provide insight into the differences...... across disciplines. This study is an analysis of the citing behaviour in journals within three science fields: biology, mathematics, and pharmacy and pharmacology. It is a statistical analysis of OAJs as well as non-OAJs including both the citing and cited side of the journal to journal citations...

  4. Web Accessibility Evaluation of Massive Open Online Courses on Geographical Information Systems

    OpenAIRE

    Calle Jiménez, Tania; Sánchez Gordón, Sandra; Luján Mora, Sergio

    2014-01-01

    This paper describes some of the challenges that exist to make accessible massive open online courses (MOOCs) on Geographical Information Systems (GIS). These courses are known by the generic name of Geo-MOOCs. A MOOC is an online course that is open to the general public for free, which causes a massive registration. A GIS is a computer application that acquire, manipulate, manage, model and visualize geo-referenced data. The goal of a Geo-MOOC is to expand the culture of spatial thinking an...

  5. Enabling worldwide access to climate simulation data: the earth system grid (ESG)

    International Nuclear Information System (INIS)

    With support from the U.S. Department of Energy's Scientific Discover Through Advanced Computing (SciDAC) program, we have developed and deployed the Earth System Grid (ESG) to make climate simulation data easily accessible to the global climate modelling and analysis community. ESG currently has 2500 registered users and manages 160 TB of data in archives distributed around the nation. From this past year alone, more than 200 scientific journal articles have been published from analyses of data delivered by the ESG

  6. Ultrasonic Multiple-Access Ranging System Using Spread Spectrum and MEMS Technology for Indoor Localization

    Directory of Open Access Journals (Sweden)

    Laurent Segers

    2014-02-01

    Full Text Available Indoor localization of persons and objects poses a great engineering challenge. Previously developed localization systems demonstrate the use of wideband techniques in ultrasound ranging systems. Direct sequence and frequency hopping spread spectrum ultrasound signals have been proven to achieve a high level of accuracy. A novel ranging method using the frequency hopping spread spectrum with finite impulse response filtering will be investigated and compared against the direct sequence spread spectrum. In the first setup, distances are estimated in a single-access environment, while in the second setup, two senders and one receiver are used. During the experiments, the micro-electromechanical systems are used as ultrasonic sensors, while the senders were implemented using field programmable gate arrays. Results show that in a single-access environment, the direct sequence spread spectrum method offers slightly better accuracy and precision performance compared to the frequency hopping spread spectrum. When two senders are used, measurements point out that the frequency hopping spread spectrum is more robust to near-far effects than the direct sequence spread spectrum.

  7. The development of access control system in Fukushima No.2 nuclear power station

    Energy Technology Data Exchange (ETDEWEB)

    Ookubo, S.; Nakai, Y.; Oohira, N.; Kishishita, S. [Tokyo Electric power Co., Tokyo (Japan); Kobayashi, H.; Sano, F. [Fuji Electric Co., Tokyo (Japan); Masuda, M.; Tajima, T.; Oohira, K. [Toshiba Corporation, Tokyo (Japan)

    2002-07-01

    A new radiation work control system has been developed for controlling the entrance and exit of workers from the radiation controlled area in a nuclear power station and has been run in the Fukushima No. 2 Nuclear Power Station of Tokyo Electric Power Co., Inc. since October, 1999. The system is designed to reduce workers burden by simplifying the operation of each equipment that controls access to radiation controlled areas, and to minimize radiation exposure by automatically acquiring dose data during each access and each task. The new system adopted electronic personal dosimeters (gamma radiation EPD) which permit data collection by radio communication, thus improving the conventional alarm-equipped personal dosimeter (EPD) and increasing reliability as primary dosimeters. Furthermore, additional electronic personal dosimeters capable of measuring beta radiation (gamma and beta radiations EPD) were also utilized in specific tasks in October 2001. After a six-month test run of these EPDs, the film badges were discontinued in April 2002 and replaced solely with the EPDs. EPDs are now used as the primary dosimetry for radiation workers.

  8. MRI diagnosis of hemangioblastoma of central nervous system%中枢神经系统血管母细胞瘤的MRI诊断

    Institute of Scientific and Technical Information of China (English)

    潘锋; 周林江; 沈健; 黄小燕

    2011-01-01

    Objective: To investigate the diagnostic value of MRI (conventional and DWI sequence) characteristics of hemangioblastoma of central nervous system. Methods : MRI features of 73 cases of hemangioblastoma of central nervous system with 81 lesions proved by pathology were analyzed retrospectively. Results: Most cases of hemangioblastoma of central nervous system showed single lesion, and most of them located in cerebellar hemisphere. 53 lesions were cysts with a mural nodule, 22 were solid tumors, and 6 were pure cyst. Nodulcs and solid mass of tumors manifested hypointensity on DWI. 19 lesions showed characteristics of cyst-in-cyst. Conclusion: MRI findings of hemangioblastoma of central nervous system are characteristic, which are closely related with pathological findings, and it provides evidence for surgery.%目的:探讨MRI(常规及DWI等序列)在中枢神经系统血管母细胞瘤诊断中的应用价值.方法:对经手术病理证实的73例血管母细胞瘤共81枚病灶的MRI表现进行回顾性分析.结果:血管母细胞瘤多为单发(67/73),小脑为最常见发病部位(61/81),可分为3型:囊伴结节型53个,实质型22个,单纯囊型6个;DWI序列肿瘤结节及实质型瘤体均呈低信号;19个病灶表现有囊中囊征象.结论:血管母细胞瘤的MRI表现具有特征性,且与其病理基础密切相关,能为手术方式的选择提供依据.

  9. Analysis of Coded FHSS Systems with Multiple Access Interference over Generalized Fading Channels

    Directory of Open Access Journals (Sweden)

    Zummo SalamA

    2008-01-01

    Full Text Available Abstract We study the effect of interference on the performance of coded FHSS systems. This is achieved by modeling the physical channel in these systems as a block fading channel. In the derivation of the bit error probability over Nakagami fading channels, we use the exact statistics of the multiple access interference (MAI in FHSS systems. Due to the mathematically intractable expression of the Rician distribution, we use the Gaussian approximation to derive the error probability of coded FHSS over Rician fading channel. The effect of pilot-aided channel estimation is studied for Rician fading channels using the Gaussian approximation. From this, the optimal hopping rate in coded FHSS is approximated. Results show that the performance loss due to interference increases as the hopping rate decreases.

  10. Analysis of Coded FHSS Systems with Multiple Access Interference over Generalized Fading Channels

    Directory of Open Access Journals (Sweden)

    Salam A. Zummo

    2009-02-01

    Full Text Available We study the effect of interference on the performance of coded FHSS systems. This is achieved by modeling the physical channel in these systems as a block fading channel. In the derivation of the bit error probability over Nakagami fading channels, we use the exact statistics of the multiple access interference (MAI in FHSS systems. Due to the mathematically intractable expression of the Rician distribution, we use the Gaussian approximation to derive the error probability of coded FHSS over Rician fading channel. The effect of pilot-aided channel estimation is studied for Rician fading channels using the Gaussian approximation. From this, the optimal hopping rate in coded FHSS is approximated. Results show that the performance loss due to interference increases as the hopping rate decreases.

  11. [Accession to the PIC/S and pharmaceutical quality system in Japan].

    Science.gov (United States)

    Katori, Noriko

    2014-01-01

    In March, 2012, Japan made the application for membership of the Pharmaceutical Inspection convention and Pharmaceutical Inspection Co-operation scheme (PIC/S) which is an international body of a GMP inspection. The globalization of pharmaceutical manufacturing and sales has been a driving force behind the decision to become a PIC/S member. For the application for membership, Japan's GMP inspectorate needs to fulfill PIC/S requirements, for example, the inspection organization has to have a quality system as a global standard. One of the other requirements is that the GMP inspectorate can access Official Medicines Control Laboratories (OMCL) having high analytical skills and also have a quality system based on ISO 17025. I would like to describe the process to make up a quality system in the National Institute of Health Sciences and also the circumstances around the PIC/S application in Japan. PMID:25707200

  12. National Geothermal Data System: an Exemplar of Open Access to Data

    Science.gov (United States)

    Allison, M. L.; Richard, S. M.; Blackman, H.; Anderson, A.

    2013-12-01

    The National Geothermal Data System's (NGDS - www.geothermaldata.org) formal launch in 2014 will provide open access to millions of datasets, sharing technical geothermal-relevant data across the geosciences to propel geothermal development and production. With information from all of the Department of Energy's sponsored development and research projects and geologic data from all 50 states, this free, interactive tool is opening new exploration opportunities and shortening project development by making data easily discoverable and accessible. We continue to populate our prototype functional data system with multiple data nodes and nationwide data online and available to the public. Data from state geological surveys and partners includes more than 5 million records online, including 1.48 million well headers (oil and gas, water, geothermal), 732,000 well logs, and 314,000 borehole temperatures and is growing rapidly. There are over 250 Web services and another 138 WMS (Web Map Services) registered in the system as of August, 2013. Companion projects run by Boise State University, Southern Methodist University, and USGS are adding millions of additional data records. The National Renewable Energy Laboratory is managing the Geothermal Data Repository which will serve as a system node and clearinghouse for data from hundreds of DOE-funded geothermal projects. NGDS is built on the US Geoscience Information Network data integration framework, which is a joint undertaking of the USGS and the Association of American State Geologists (AASG). NGDS is fully compliant with the White House Executive Order of May 2013, requiring all federal agencies to make their data holdings publicly accessible online in open source, interoperable formats with common core and extensible metadata. The National Geothermal Data System is being designed, built, deployed, and populated primarily with grants from the US Department of Energy, Geothermal Technologies Office. To keep this operational

  13. NATIONAL GEOTHERMAL DATA SYSTEM: AN EXEMPLAR OF OPEN ACCESS TO DATA

    Energy Technology Data Exchange (ETDEWEB)

    Blackman, Harold [Arizona Geological Survey; Blackman, Harold M. [Arizona Geological Survey; Blackman, Harold M. [Arizona Geological Survey; Blackman, Harold [Boise State University; Blackman, Harold [United States Department of Energy; Blackman, Harold

    2013-10-01

    The formal launch of National Geothermal Data System (NGDS – www.geothermaldata.org) in 2014 will provide open access to technical geothermal-relevant data from all of the Department of Energy- sponsored geothermal development and research projects and geologic data from all 50 states. By making data easily discoverable and accessible this system will open new exploration opportunities and shorten project development. The prototype data system currently includes multiple data nodes, and nationwide data online and available to the public, indexed through a single catalog under construction at http://search.geothermaldata.org. Data from state geological surveys and partners includes more than 5 million records online, including 1.48 million well headers (oil and gas, water, geothermal), 732,000 well logs, and 314,000 borehole temperatures and is growing rapidly. There are over 250 Web services and another 138 WMS (Web Map Services) registered in the system as of August, 2013. Additional data record is being added by companion projects run by Boise State University, Southern Methodist University, and the USGS. The National Renewable Energy Laboratory is managing the Geothermal Data Repository, an NGDS node that will be a clearinghouse for data from hundreds of DOE-funded geothermal projects. NGDS is built on the US Geoscience Information Network (USGIN) data integration framework, which is a joint undertaking of the USGS and the Association of American State Geologists (AASG). NGDS is fully compliant with the White House Executive Order of May 2013, requiring all federal agencies to make their data holdings publicly accessible online in open source, interoperable formats with common core and extensible metadata. The National Geothermal Data System is being designed, built, deployed, and populated primarily with grants from the US Department of Energy, Geothermal Technologies Office. To keep this operational system sustainable after the original implementation will

  14. Use of the tools of an operating system kernel to control access to the entities of application servers

    International Nuclear Information System (INIS)

    A method has been proposed for using the tools of kernel of an operating system to control access to the entities of application servers. The possibility of using an information protection system incorporated into the operating system to store and implement security policy has been demonstrated for a database management system

  15. Smartphone-based system to improve transportation access for the cognitively impaired.

    Science.gov (United States)

    Anderson, Shane M; Riehle, Timothy H; Lichter, Patrick A; Brown, Allen W; Panescu, Dorin

    2015-08-01

    This project developed and evaluated a smartphone-based system to improve mobility and transportation access for the cognitively impaired. The proposed system is intended to allow the cognitively impaired to use public transportation systems, community transportation and dedicated transportation services for the disabled with greater ease and safety. Individuals with cognitive disabilities are often unable to operate an automobile, or may require a prolonged recovery period before resuming driving. Public transportation systems represent a significant means to allow these individuals to maintain independence. Yet public transportation systems can pose significant challenges to individuals with cognitive impairment. The goal of this project is to develop a system to reduce these barriers via a technological solution consisting of components developed both for the cognitively impaired user and their caregiver or family member. The first component consists of a cognitive prosthetic device featuring traditional memory cueing and reminders as well as custom location-based transportation specific functions. This cognitive mobility assistant will leverage the computing power and GPS location determination capabilities of inexpensive, powerful smart phones. The second component consists of a management application which offers caregivers the ability to configure and program the reminder and transit functions remotely via the Internet. Following completion of the prototype system a pilot human test was performed with cognitively disabled individuals and family members or caregivers to assess the usability and acceptability of both system components. PMID:26738091

  16. Interface of the transport systems research vehicle monochrome display system to the digital autonomous terminal access communication data bus

    Science.gov (United States)

    Easley, W. C.; Tanguy, J. S.

    1986-01-01

    An upgrade of the transport systems research vehicle (TSRV) experimental flight system retained the original monochrome display system. The original host computer was replaced with a Norden 11/70, a new digital autonomous terminal access communication (DATAC) data bus was installed for data transfer between display system and host, while a new data interface method was required. The new display data interface uses four split phase bipolar (SPBP) serial busses. The DATAC bus uses a shared interface ram (SIR) for intermediate storage of its data transfer. A display interface unit (DIU) was designed and configured to read from and write to the SIR to properly convert the data from parallel to SPBP serial and vice versa. It is found that separation of data for use by each SPBP bus and synchronization of data tranfer throughout the entire experimental flight system are major problems which require solution in DIU design. The techniques used to accomplish these new data interface requirements are described.

  17. Ocean Surface Topography Mission (OSTM) /Jason-2: Near Real-Time Altimetry Validation System (NRTAVS) QA Reports (NODC Accession 0044984)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains the descriptions for the OSTM/Jason-2 Near Real-Time Altimetry Validation System Quality Reports, which are served through the NOAA/NESDIS...

  18. Simulation of the expected performance of INSERT: A new multi-modality SPECT/MRI system for preclinical and clinical imaging

    Science.gov (United States)

    Busca, P.; Fiorini, C.; Butt, A. D.; Occhipinti, M.; Peloso, R.; Quaglia, R.; Schembari, F.; Trigilio, P.; Nemeth, G.; Major, P.; Erlandsson, K.; Hutton, B. F.

    2014-01-01

    A new multi-modality imaging tool is under development in the framework of the INSERT (INtegrated SPECT/MRI for Enhanced Stratification in Radio-chemo Therapy) project, supported by the European Community. The final goal is to develop a custom SPECT apparatus, that can be used as an insert for commercially available MRI systems such as 3 T MRI with 59 cm bore diameter. INSERT is expected to offer more effective and earlier diagnosis with potentially better outcome in survival for the treatment of brain tumors, primarily glioma. Two SPECT prototypes will be developed, one dedicated to preclinical imaging, the second one dedicated to clinical imaging. The basic building block of the SPECT detector ring is a small 5 cm×5 cm gamma camera, based on the well-established Anger architecture with a continuous scintillator readout by an array of silicon photodetectors. Silicon Drift Detectors (SDDs) and Silicon PhotoMultipliers (SiPM) are being considered as possible scintillator readout, considering that the detector choice plays a predominant role for the final performance of the system, such as energy and spatial resolution, as well as the useful field of view of the camera. Both solutions are therefore under study to evaluate their performances in terms of field of view (FOV), spatial and energy resolution. Preliminary simulations for both the preclinical and clinical systems have been carried out to evaluate resolution and sensitivity.

  19. A hybrid system for the semantic annotation of sulco-gyral anatomy in MRI images.

    Science.gov (United States)

    Mechouche, Ammar; Morandi, Xavier; Golbreich, Christine; Gibaud, Bernard

    2008-01-01

    This paper presents an interactive system for the annotation of brain anatomical structures in Magnetic Resonance Images. The system is based on hybrid knowledge and techniques. First, it exploits both numerical knowledge from atlases and symbolic knowledge from a rule-extended ontology represented in OWL, the Web ontology language, and combines them with graphical data about cortical sulci, automatically extracted from the images. Second, the annotations of the parts of gyri and of sulci located in a region of interest are obtained with different reasoning techniques: Constraint Satisfaction Solving and Description Logics techniques. Preliminary experiments have been achieved on normal and also pathological data. The results obtained so far are very promising. PMID:18979820

  20. Concurrent TMS-fMRI Reveals Interactions between Dorsal and Ventral Attentional Systems

    DEFF Research Database (Denmark)

    Leitao, Joana; Thielscher, Axel; Tuennerhoff, Johannes;

    2015-01-01

    detected weak visual targets that were presented in the lower-left visual field on 50% of the trials. Further, we manipulated the presence/absence of task-irrelevant auditory signals. Critically, on each trial we applied 10 Hz bursts of four TMS (or Sham) pulses to the intraparietal sulcus (IPS). IPS......Adaptive behavior relies on combining bottom-up sensory inputs with top-down control signals to guide responses in line with current goals and task demands. Over the past decade, accumulating evidence has suggested that the dorsal and ventral frontoparietal attentional systems are recruited......-TMS relative to Sham-TMS increased activation in the parietal cortex regardless of sensory stimulation, confirming the neural effectiveness of TMS stimulation. Visual targets increased activations in the anterior insula, a component of the ventral attentional system responsible for salience detection...

  1. An efficient FPGA implementation of MRI image filtering and tumor characterization using Xilinx system generator

    CERN Document Server

    Christe, S Allin; Kandaswamy, A

    2012-01-01

    This paper presents an efficient architecture for various image filtering algorithms and tumor characterization using Xilinx System Generator (XSG). This architecture offers an alternative through a graphical user interface that combines MATLAB, Simulink and XSG and explores important aspects concerned to hardware implementation. Performance of this architecture implemented in SPARTAN-3E Starter kit (XC3S500E-FG320) exceeds those of similar or greater resources architectures. The proposed architecture reduces the resources available on target device by 50%.

  2. Statistical analysis of MRI-only based dose planning

    DEFF Research Database (Denmark)

    Korsholm, M. E.; Waring, L. W.; Paulsen, Rasmus Reinhold;

    2012-01-01

    . MRIonly based RT eliminates these errors and reduce the time and costs of a CT scan. The aim of this study is to investigate the dosimetric differences of a treatment plan when the dose calculation is based on MRI as compared to CT. Materials and Methods: Four diagnostic groups are investigated; 12...... as a clinically approved treatment plan. The treatment planning software is Eclipse v.10.0 (Varian Medical Systems). The dose calculation based on MRI data is evaluated in two different ways; a homogeneous density assigned MRI (MRI unit), where the entire body is assigned an HU equal to water and a heterogeneous...... density assigned MRI (MRI bulk) where in addition the CT segmented bone is transferred to the MRI and assigned an age dependent HU based on ICRU report 46. The CT based clinical treatment plan and structure set are registered to the corresponding MRI unit and MRI bulk. The body is outlined on both the MRI...

  3. Lung cancer survival among black and white patients in an equal access health system

    Science.gov (United States)

    Zheng, Li; Enewold, Lindsey; Zahm, Shelia H.; Shriver, Craig D.; Zhou, Jing; Marrogi, Aizen; McGlynn, Katherine A.; Zhu, Kangmin

    2014-01-01

    Background Racial disparities in lung cancer outcomes have been observed in the general population. However, it is unclear whether survival differences persist when patients have equal access to healthcare. Our objective was to determine if lung cancer survival differed among black and white patients in the U.S. Military Health System (MHS), an equal access healthcare system. Methods The study subjects were 10,181 black and white patients identified through the Department of Defense’s Automated Central Tumor Registry, who were ≥20 years old and diagnosed with lung cancer between 1990 and 2003. Racial differences in all-cause survival were examined using the Kaplan–Meier method and Cox proportional hazards regression models stratified by histology. For comparison, survival rates in the general population were calculated using Surveillance, Epidemiology and End Results (SEER)-9 data. Results Analyses included 9,154 white and 1,027 black patients: 1,834 small cell lung cancers, 3,876 adenocarcinomas, 2,741 squamous cell carcinomas, and 1,730 large cell carcinomas. Although more favorable crude survival was observed among black patients than white patients with small cell lung cancer (p=0.04), survival was similar between the two groups after covariate adjustment. Racial differences in survival were non-significant for adenocarcinomas, squamous cell carcinomas and large cell carcinomas. Survival rates appeared to be better in the MHS than in the general population. Conclusions and Impact All-cause survival was similar among black and white lung cancer patients in the MHS. Providing equal access to healthcare may eliminate racial disparities in lung cancer survival while improving the outcome of all cases. PMID:22899731

  4. Early assessment of sub-clinical cardiac involvement in systemic sclerosis (SSc) using delayed enhancement cardiac magnetic resonance (CE-MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Di Cesare, Ernesto, E-mail: ernesto.dicesare@cc.univaq.it [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy); Battisti, Sara; Di Sibio, Alessandra [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy); Cipriani, Paola; Giacomelli, Roberto; Liakouli, Vasiliky; Ruscitti, Piero [Rheumatology Clinic, Department of Internal Medicine and Public Health, University of L’Aquila, L’Aquila (Italy); Masciocchi, Carlo [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy)

    2013-06-15

    Objectives: Systemic sclerosis heart involvement (SHI) is one of systemic sclerosis (SSc) most frequent complications, both in diffuse (dcSSc) and limited (lcSSc) cutaneous forms of disease. Nowadays, SHI is a major factor decreasing SSc survival rate because, when clinically evident, is associated with 70% of mortality at 5 years. SHI shows different forms, primary and/or secondary. Primary myocardial SHI is characterized by fibrosis. Aim of our study is to assess the presence and pattern of fibrosis as detected by cardiac magnetic resonance (CMR) in systemic sclerosis. Methods: In this study, we used CE-MRI (contrast enhanced-MRI) in 58 female SSc patients. Images were evaluated to obtain functional parameters and to see presence, location and pattern (nodular, linear or diffuse) of myocardial LE, sign of fibrosis. CE-MRI findings were correlated with patients clinical setting. Results: Myocardial fibrosis was detected in 25 of 58 patients (43%). The main finding observed in 16 of these 25 patients was a late enhancement showing a linear pattern, without coronary distribution and sparing the sub-endocardial myocardial layers. A patchy nodular enhancement pattern was observed in 9 patients (36%). Patients with linear pattern presented dcSSc, on the contrary patients with nodular LE displayed the lcSSc form. Conclusions: This study shows that CE-MRI is a reliable technique to detect SHI earlier than other methods. SHI increase passive myocardial stiffness, proportional to collagen deposition degree, leading to cardiac remodelling with possible development of heart failure, even with normal ejection fraction. An early treatment of SHI might improve SSc patients outcome.

  5. Simulation of the expected performance of INSERT: A new multi-modality SPECT/MRI system for preclinical and clinical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Busca, P., E-mail: busca@elet.polimi.it [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano (Italy); Fiorini, C., E-mail: carlo.fiorini@polimi.it [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano (Italy); Butt, A.D.; Occhipinti, M.; Peloso, R.; Quaglia, R.; Schembari, F.; Trigilio, P. [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano (Italy); Nemeth, G.; Major, P. [Mediso Medical Imaging Systems, Alsotorokvesz 14, H-1022 Budapest (Hungary); Erlandsson, K. [University College London, Gower Street, WC1E 6BT London (United Kingdom); Hutton, B.F. [University College London, Gower Street, WC1E 6BT London (United Kingdom); Centre for Medical Radiation Physics, University of Wollongong, NSW 2522 (Australia)

    2014-01-11

    A new multi-modality imaging tool is under development in the framework of the INSERT (INtegrated SPECT/MRI for Enhanced Stratification in Radio-chemo Therapy) project, supported by the European Community. The final goal is to develop a custom SPECT apparatus, that can be used as an insert for commercially available MRI systems such as 3 T MRI with 59 cm bore diameter. INSERT is expected to offer more effective and earlier diagnosis with potentially better outcome in survival for the treatment of brain tumors, primarily glioma. Two SPECT prototypes will be developed, one dedicated to preclinical imaging, the second one dedicated to clinical imaging. The basic building block of the SPECT detector ring is a small 5 cm×5 cm gamma camera, based on the well-established Anger architecture with a continuous scintillator readout by an array of silicon photodetectors. Silicon Drift Detectors (SDDs) and Silicon PhotoMultipliers (SiPM) are being considered as possible scintillator readout, considering that the detector choice plays a predominant role for the final performance of the system, such as energy and spatial resolution, as well as the useful field of view of the camera. Both solutions are therefore under study to evaluate their performances in terms of field of view (FOV), spatial and energy resolution. Preliminary simulations for both the preclinical and clinical systems have been carried out to evaluate resolution and sensitivity. -- Highlights: • We introduce INSERT, a new multi-modality SPECT/MRI instrument. • We propose two possible photodetectors (SDD, SiPM) for the scintillators readout. • We show possible results for INSERT, based on simulations.

  6. FLOSYS--a web-accessible workflow system for protocol-driven biomolecular sequence analysis.

    Science.gov (United States)

    Badidi, E; Lang, B F; Burger, G

    2004-11-01

    FLOSYS is an interactive web-accessible bioinformatics workflow system designed to assist biologists in multi-step data analyses. FLOSYS allows the user to create complex analysis pathways (protocols) graphically, similar to drawing a flowchart: icons representing particular bioinformatics tools are dragged and dropped onto a canvas and lines connecting those icons are drawn to specify the relationships between the tools. In addition, FLOSYS permits to select input-data, execute the protocol and store the results in a personal workspace. The three-tier architecture of FLOSYS has been implemented in Java and uses a relational database system together with new technologies for distributed and web computing such as CORBA, RMI, JSP and JDBC. The prototype of FLOSYS, which is part of the bioinformatics workbench AnaBench, is accessible on-line at http://malawimonas.bcm.umontreal.ca: 8091/anabench. The entire package is available on request to academic groups who wish to have a customized local analysis environment for research or teaching.

  7. Usefulness of breath-hold cardiac cine MR imaging with a middle field MRI system

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Kentaro; Sato, Kiyoto; Aono, Masaki; Inoshita, Kenji; Utsumi, Naoko [Kagawa Inoshita Hospital, Ohnohara (Japan)

    1999-07-01

    To assess the accuracy of contrast-enhanced, single breath-hold cine MR imaging in calculating left ventricular volume and ejection fraction, we compared MR measurements with those obtained by using cine ventriculography in 60 patients. Fast cine MR images were acquired with a middle field MR system (0.5 T). A breath-hold single slice multi-phase fast gradient-echo (Fast Card) sequence was used to obtain fast cine MR images with the following parameters; TR of 16 ms, TE of 3 ms, flip angle of 30 degree, matrix elements of 256 x 128, view per segment of 6, field of view of 350 x 260 mm and one excitation. Left ventricular end-diastolic volume and ejection fraction obtained with contrast-enhanced Fast Card correlated well with those obtained with cine ventriculography (end-diastolic volume, y=1.00x+14.0, r=0.904, p<0.001; ejection fraction, y=0.961x+2.8, r=0.936, p<0.001). Our results show that contrast enhanced breath-hold cardiac cine MR imaging on horizontal long-axis view using a middle field MR system is an accurate method for evaluating left ventricular volume and ejection fraction. (author)

  8. Enhancing Access to NASA Data via Seamless Integration Into Decision Support Systems: two Examples

    Science.gov (United States)

    Teng, W.; Rui, H.; Rishe, N.; Tetrault, R.

    2005-12-01

    The amount and variety of information that can be extracted from NASA satellite data form a rich resource that is largely untapped by the applications user community. In part, this is because of the complexity and cost of using such data. Many approaches, such as subsetting, have been taken to ameliorate this situation. Mostly, however, they have not sufficiently addressed the core needs of the applications community. The latter is generally not interested in the data per se (e.g., how they are processed), but rather in the specific measurements (e.g., surface rain) from the data, which can be infused in some decision support system. These measurements should ideally be seamlessly accessible. To rapidly bridge the gap between NASA information systems and services and the practical needs of the applications (and research) community, the Goddard Earth Sciences Data and Information Services Center (GES DISC) has collaborated with the Florida International University High Performance Database Research Center (FIU HPDRC) and the U.S. Department of Agriculture Foreign Agricultural Service (USDA FAS) to demonstrate the feasibility of making NASA data more easily and seamlessly accessible via the Web, from within the FIU's TerraFly and the FAS' Crop Explorer environments, respectively. TerraFly currently serves a broad segment of the research and applications community (some 10,000 unique users per day), by facilitating the access to various textual, remotely sensed, and vector data. Crop Explorer is the primary decision support tool used by the FAS analysts to monitor the production, supply, and demand of agricultural commodities worldwide. The key NASA information system providing the data integrated into TerraFly and Crop Explorer is the GES DISC Interactive Online Visualization and Analysis Infrastructure (Giovanni), which enables users to easily and quickly obtain science information from the data, without having to download and handle large amounts of data. The

  9. Study on Mandatory Access Control in a Secure Database Management System

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper proposes a security policy model for mandatory access control in class B1 database management system whose level of labeling is tuple. The relation-hierarchical data model is extended to multilevel relation-hierarchical data model. Based on the multilevel relation-hierarchical data model, the concept of upper-lower layer relational integrity is presented after we analyze and eliminate the covert channels caused by the database integrity. Two SQL statements are extended to process polyinstantiation in the multilevel secure environment. The system is based on the multilevel relation-hierarchical data model and is capable of integratively storing and manipulating multilevel complicated objects (e. g., multilevel spatial data) and multilevel conventional data ( e. g., integer. real number and character string).

  10. Widened Participation and Unequal Access to the System of Higher Education in Denmark

    DEFF Research Database (Denmark)

    Munk, Martin D.; Thomsen, Jens Peter

    This paper deals with access to Higher Education (HE), more specifically with social differentiation within Danish university field of studies and institutions. We use Danish register data and investigate choice of field of study and choice of university institution while controlling for a range...... of student background variables. Theoretically we draw on notions of forms of capital and of channelling, diversion and effectively maintained inequality in the educational system. We find that it is important to differentiate not only between fields of studies, but also between university institutions......, in explaining the processes of inequality and differentiation in the Danish University system. Here two dimensions are important: the university institutions degree of social selectivity and whether it is has a ‘classic’ university profile (liberal arts) or a more ‘modern’ applied-oriented profile....

  11. Results of an Iridium-Based Data Communication System Providing Internet Access to Polar Expeditions

    Science.gov (United States)

    Mohammad, A.; Frost, V.; Braaten, D.

    2003-12-01

    ' W) from June 23-July 17, 2003. We measured the reliability, throughput and general performance of this system over periods of up to 24 hours. This included delay, loss, throughput, call drops/up-time, relative signal strengths, connection time and number of connection retries. The system was also successfully tested while moving across the ice sheet at speeds of up to 30 km/h. We were successful in uploading and downloading large files (.2MB to 7.2MB) to the Internet. In combination with a modified Wi-Fi deployment, wireless Internet access was also provided to the entire NorthGRIP camp for a few days. The field experiments have shown that standard Internet protocols combined with MLPPP and Iridium modems can provide Internet access for polar expeditions at useful data rates. The 4-modem configuration we tested was observed to be >90 % efficient, e.g., a 2.5 MB video file was transferred in 35 min. at 9.524 Kb/s. The system had an average up-time of over 90 % and thus is stable and suitable for autonomous operation. Mobile performance results were very similar to that of stationary systems. While the end-to-end network architecture developed to provide Internet access worked well, the system round trip time is significant ( ˜ 1.8 seconds), which can impair real time interactions.

  12. Joint Compression-Segmentation of functional MRI Data

    DEFF Research Database (Denmark)

    Zhang, N.; Wu, Mo; Forchhammer, Søren;

    2005-01-01

    with the classification of the background is used to segment the regions of interest from the background. Significantly higher lossless compression of 4D fMRI than JPEG 2000 and JPEG-LS is achieved by both methods. The 2D classification map for compression can also be used for image segmentation in 3D space for analysis...... and recognition purposes. This segmentation supports object-based random access to very large 4D data volumes. The time sequence of DPCM prediction residuals can be analyzed to yield information on the responses of the imaged anatomy to the stimuli. The proposed wavelet method provides an object......Functional Magnetic Resonance Imaging (fMRI) data sets are four dimensional (4D) and very large in size. Compression can enhance system performance in terms of storage and transmission capacities. Two approaches are investigated: adaptive DPCM and integer wavelets. In the DPCM approach, each voxel...

  13. Design of an MRI quadrature-data acquisition card

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A design of a quadrature-data acquisition card based on peripheral component interconnect (PCI) bus for mini-type magnetic resonance imaging (MRI) system is reported. It uses two high speed analog-to-digital converters (ADCs) to sample the MRI signals and two static random access memories (SRAMs) to store the data which will be read to the computer by PCI bus after sampling. All the logic control signals on the card are generated by the field programmable gate array (FPGA). The software Foundation3.1 is used to design the FPGA and achieve useful result after simulating and implementing. The card has some merits that normal commercial cards do not have. For example, the sampling parameters can be varied according to different pulse sequences.

  14. A Hybrid System for Acquisition of and Access to the Data from Foundry Technical Standards

    Directory of Open Access Journals (Sweden)

    A. Macioł

    2007-07-01

    Full Text Available The growing importance of automatized systems for interchange of commercial and technical information prompts searching for new forms of knowledge modelling. One of the possible solutions presented in this article is the use of relational databases for acquisition of information comprised in technical standards and of a rule-based reasoning system providing access to these bases. The study describes the structure of a database created under the assumption that concepts describing knowledge will be recorded in data collecting system and not in relational schema. The user is free to define by himself the structure of the knowledge without the need of introducing any changes to the relational schema. At the same time, the reasoning system enables very efficient knowledge searching. At present, tests are carried out on a software operating on a MS SQL Server. The project work and test performance of the system confirm that the adopted assumptions have been right and correct. The development of a new interface is anticipated using internet techniques. As a next step, the information resources collected in the system will be successively expanded using also information sources other than the technical standards.

  15. Face Recognition for Access Control Systems Combining Image-Difference Features Based on a Probabilistic Model

    Science.gov (United States)

    Miwa, Shotaro; Kage, Hiroshi; Hirai, Takashi; Sumi, Kazuhiko

    We propose a probabilistic face recognition algorithm for Access Control System(ACS)s. Comparing with existing ACSs using low cost IC-cards, face recognition has advantages in usability and security that it doesn't require people to hold cards over scanners and doesn't accept imposters with authorized cards. Therefore face recognition attracts more interests in security markets than IC-cards. But in security markets where low cost ACSs exist, price competition is important, and there is a limitation on the quality of available cameras and image control. Therefore ACSs using face recognition are required to handle much lower quality images, such as defocused and poor gain-controlled images than high security systems, such as immigration control. To tackle with such image quality problems we developed a face recognition algorithm based on a probabilistic model which combines a variety of image-difference features trained by Real AdaBoost with their prior probability distributions. It enables to evaluate and utilize only reliable features among trained ones during each authentication, and achieve high recognition performance rates. The field evaluation using a pseudo Access Control System installed in our office shows that the proposed system achieves a constant high recognition performance rate independent on face image qualities, that is about four times lower EER (Equal Error Rate) under a variety of image conditions than one without any prior probability distributions. On the other hand using image difference features without any prior probabilities are sensitive to image qualities. We also evaluated PCA, and it has worse, but constant performance rates because of its general optimization on overall data. Comparing with PCA, Real AdaBoost without any prior distribution performs twice better under good image conditions, but degrades to a performance as good as PCA under poor image conditions.

  16. Incident and Trafficking Database: New Systems for Reporting and Accessing State Information

    International Nuclear Information System (INIS)

    The IAEA's Incident and Trafficking Database (ITDB) is the Agency's authoritative source for information on incidents in which nuclear and other radioactive material is out of national regulatory control. It was established in 1995 and, as of June 2014, 126 States participate in the ITDB programme. Currently, the database contains over 2500 confirmed incidents, out of which 21% involve nuclear material, 62% radioactive source and 17% radioactively contaminated material. In recent years, the system for States to report incidents to the ITDB has been evolving — moving from fax-based to secure email and most recently to secure on-line reporting. A Beta version of the on-line system was rolled out this June, offering a simple, yet secure, communication channel for member states to provide information. In addition the system serves as a central hub for information related to official communication of the IAEA with Member States so some communication that is traditionally shared by e-mail does not get lost when ITDB counterparts change. In addition the new reporting system incorporates optional features that allow multiple Member State users to collaboratively contribute toward an INF. States are also being given secure on-line access to a streamlined version of the ITDB. This improves States' capabilities to retrieve and analyze information for their own purposes. In addition, on-line access to ITDB statistical information on incidents is available to States through an ITDB Dashboard. The dashboard contains aggregate information on number and types of incidents, material involved, as well some other statistics related to the ITDB that is typically provided in the ITDB Quarterly reports. (author)

  17. Magnetic Resonance Imaging (MRI)

    Science.gov (United States)

    ... How Can I Help a Friend Who Cuts? Magnetic Resonance Imaging (MRI) KidsHealth > For Teens > Magnetic Resonance Imaging (MRI) Print A A A Text Size What's ... Exam Safety Getting Your Results What Is MRI? Magnetic resonance imaging (MRI) is a type of safe, painless testing ...

  18. The role of FDG-PET, HMPAO-SPET and MRI in the detection of brain involvement in patients with systemic lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Kao Chiahung [Department of Nuclear Medicine, Taichung Veterans General Hospital, Taichung (Taiwan, Province of China); Lan Jungliang [Division of Rheumatology, Taichung Veterans General Hospital, Taichung (Taiwan, Province of China); ChangLai Shengping [Department of Nuclear Medicine, Chung-Shan Medical and Dental College, Taichung (Taiwan, Province of China); Liao Kokaung [Electron Microscopic Laboratory, Chung-Shan Medical and Dental College, Taichung (Taiwan, Province of China); Yen Rouhfang; Chieng Poonung [Department of Nuclear Medicine, National Taiwan University Hospital, Taipei (Taiwan, Province of China)

    1999-02-01

    Involvement of the brain is one of the most important complications of systemic lupus erythematosus (SLE); however, its diagnosis is difficult due to the lack of effective imaging methods. We combined three brain imaging modalities - positron emission tomography with fluorine-18 2-fluoro-2-deoxy-d-glucose (FDG-PET), single-photon emission computed tomography with technetium-99m hexamethylpropylene amine oxime (HMPAO-SPET) and magnetic resonance imaging (MRI) - in order to detect brain involvement in SLE. Thirty-seven SLE patients, aged 22-45 years, were divided into three groups. Group 1 (G1) consisted of ten patients with major neuropsychiatric manifestations; group 2 (G2) consisted of 15 patients with minor manifestations; and group 3 (G3) consisted of 12 patients without manifestations. FDG-PET findings were abnormal in 51% of patients: 90% of G1, 67% of G2 and 0% of G3 patients respectively. HMPAO-SPET findings were abnormal in 62% of patients: 100% of G1, 73% of G2 and 17% of G3 patients respectively. MRI findings were abnormal in 35% of patients: 70% of G1, 40% of G2 and 0% of G3 patients respectively. Grey matter was more commonly involved than white matter; 62% of patients presented with lesions in the cerebral cortex, 27% with lesions in the basal ganglion, 5% with lesions in the cerebellum, and 19% with lesions in white matter. No white matter lesions were found on FDG-PET or HMPAO-SPET. However, in 19% of patients, MRI demonstrated abnormally high signal lesions in white matter. Forty-three percent of cases had positive serum anticardiolipin antibodies (ACA). However, ACA was not related to FDG-PET, HMPAO-SPET or MRI findings. It may be concluding that HMPAO-SPET is a more sensitive tool for detecting brain involvement in SLE patients when compared with FDG-PET or MRI. However, MRI is necessary for detecting lesions in white matter. (orig.) With 3 figs., 2 tabs., 46 refs.

  19. Limbic system perfusion in Alzheimer's disease measured by MRI-coregistered HMPAO SPET

    International Nuclear Information System (INIS)

    The goal of this study was to perform a systematic, semi-quantitative analysis of limbic perfusion in patients with Alzheimer's disease (AD) using coregistered single-photon emission tomography (SPET) images aligned to magnetic resonance (MR) images. Limbic perfusion in 40 patients with mild to moderate AD was compared with that of 17 age-, sex-, and education-matched normal controls (NC). HMPAO SPET scans and 3D T1-weighted MR images were acquired for each subject. Structures of the limbic system (i.e. hippocampus, amygdala, anterior thalamus, hypothalamus, mamillary bodies, basal forebrain, septal area and cingulate, orbitofrontal and parahippocampal cortices) were traced on the MR images and transferred to the coregistered SPET scans. Perfusion ratios for all limbic regions were calculated relative to cerebellar perfusion. General linear model multivariate analysis revealed that, overall, limbic structures showed significant hypoperfusion (F=7.802, P2=0.695) in AD patients compared with NC. Greatest differences (d≥0.8) were found in the hippocampus, as well as all areas of the cingulate cortex. Significant relative hypoperfusion was also apparent in the parahippocampal cortex, amygdala/entorhinal cortex, septal area and anterior thalamus, all of which showed medium to large effect sizes (d=0.6-0.8). No significant relative perfusion differences were detected in the basal forebrain, hypothalamus, mamillary bodies or orbitofrontal cortex. Logistic regression indicated that posterior cingulate cortex perfusion was able to discriminate AD patients from NC with 93% accuracy (95% sensitivity, 88% specificity). The current results suggest that most, but not all, limbic structures show significant relative hypoperfusion in AD. These findings validate previous post-mortem studies and could be useful in improving diagnostic accuracy, monitoring disease progression and evaluating potential treatment strategies in AD. (orig.)

  20. Difficulties in accessing and availing of public health care systems among rural population in Chittoor District, Andhra Pradesh

    Directory of Open Access Journals (Sweden)

    Geetha Lakshmi Sreerama

    2015-01-01

    Full Text Available Context: Despite policies to make health care accessible to all, it is not universally accessible. Frequent evaluation of barriers to accessibility of health care services paves path for improvement. Hence, present study is undertaken to evaluate the factors and public health policies influencing health care access to rural people in Chittoor District, Andhra Pradesh, which can be interpolated for other regions. Aims: To assess knowledge, perceptions, availing of public health care services, barriers to health care access in Chittoor District, Andhra Pradesh. Settings and Design: Cross-sectional, hospital-based survey in the Government Maternity Hospital (GMH, Tirupati, a tertiary care center. Materials and Methods: Fifty women delivered normally in GMH through convenient sampling technique. Data collected on standardized pro forma as per IMS Institute of Healthcare Informatics. Statistical Analysis Used: Is done through MS Excel 2007, Epi Info 7 (of Centres for Disease Control and Prevention, Atlanta, USA and frequencies were described. Results: Distance, waiting hours, societal responsibility, nature of the illness, presumed commercialization of Medicare system, attitudes of health care providers, and loss of wages were not barriers for accessing health care. Accredited Social Health Activist (ASHA and availability of ambulance services made great improvements in health care accessibility. Absenteeism of health care providers is a problem. Conclusions: Expanding the ambulance services and ASHA network will be an effective measure for further accessibility to health care. Absenteeism of health care providers needs correction.

  1. An approach to assessing multicity implementation of healthful food access policy, systems, and environmental changes.

    Science.gov (United States)

    Silberfarb, Laura Oliven; Savre, Sonja; Geber, Gayle

    2014-01-01

    Local governments play an increasingly important role in improving residents' access to healthful food and beverages to reduce obesity and chronic disease. Cities can use multiple strategies to improve community health through, for example, land use and zoning policies, city contracting and procurement practices, sponsorship of farmers markets and community gardens, and vending and concession practices in parks and recreation facilities. With 41 cities in the Hennepin County Human Services and Public Health Department jurisdiction, the county undertook to measure the extent to which cities were engaged in making policy, systems, and environmental (PSE) changes to increase residents' access to healthful food. The results revealed that some cities, particularly those with higher resident demand for healthful food, are making nationally recommended PSE changes, such as sponsoring farmers markets and community gardens. Cities have moved more slowly to make changes in areas with perceived negative cost consequences or lesser public demand, such as parks and recreation vending and concessions. This article describes the assessment process, survey tools, findings, and implications for other health departments seeking to undertake a similar assessment. PMID:24762528

  2. AGRICULTURAL COOPERATIVE FIRMS: BUDGETARY ADJUSTMENTS AND ANALYSIS OF CREDIT ACCESS APPLYING SCORING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Giuseppe Bonazzi

    2014-01-01

    Full Text Available Cooperatives are one of the most important types of companies in the agricultural sector. Cooperatives allow overcoming the limitations of the fragmentation of agricultural property, increasing the level of production of small-sized farms and selling the product so that it reaches a sufficient critical mass. Moreover, cooperatives are often characterized by undercapitalization and even difficult credit access because banks conduct their analysis applying rating systems that do not take into account the typicality of the cooperative budget. To assess this topic, in this article, an analysis has been conducted on a sample of 100 cooperatives, making adjustments to the annual budget in order to consider the typicality of their annual accounts. The results of the analysis show that suggested adjustments allow a more correct expression of the economic results and capital adequacy of the cooperative and that the results, expressed in terms of scoring, are higher than that achieved by a traditional analysis. This methodology could improve the credit access capacity for agricultural cooperatives and then reduce financial constraints, particularly in developing countries.

  3. System architecture and information model for integrated access to distributed biomedical information

    Science.gov (United States)

    Kim, Dongkyu; Alaoui, Adil; Levine, Betty; Leondaridis, Leonidas; Shields, Peter; Byers, Steve; Cleary, Kevin

    2009-02-01

    The current trend towards systems medicine will rely heavily on computational and bioinformatics capabilities to collect, integrate, and analyze massive amounts of data from disparate sources. The objective is to use this information to make medical decisions that improve patient care. At Georgetown University Medical Center, we are developing an informatics capability to integrate several research and clinical databases. Our long term goal is to provide researchers at Georgetown's Lombardi Comprehensive Cancer Center better access to aggregated molecular and clinical information facilitating the investigation of new hypotheses that impact patient care. We also recognize the need for data mining tools and intelligent agents to help researchers in these efforts. This paper describes our initial work to create a flexible platform for researchers and physicians that provides access to information sources including clinical records, medical images, genomic, epigenomic, proteomic and metabolomic data. This paper describes the data sources selected for this pilot project and possible approaches to integrating these databases. We present the different database integration models that we considered. We conclude by outlining the proposed Information Model for the project.

  4. New System For Tokamak T-10 Experimental Data Acquisition, Data Handling And Remote Access

    International Nuclear Information System (INIS)

    For carrying out the experiments on nuclear fusion devices in the Institute of Nuclear Fusion, Moscow, a system for experimental data acquisition, data handling and remote access (further 'DAS-T10') was developed and has been used in the Institute since the year 2000. The DAS-T10 maintains the whole cycle of experimental data handling: from configuration of data measuring equipment and acquisition of raw data from the fusion device (the Device), to presentation of math-processed data and support of the experiment data archive. The DAS-T10 provides facilities for the researchers to access the data both at early stages of an experiment and well afterwards, locally from within the experiment network and remotely over the Internet.The DAS-T10 is undergoing a modernization since the year 2007. The new version of the DAS-T10 will accommodate to modern data measuring equipment and will implement improved architectural solutions. The innovations will allow the DAS-T10 to produce and handle larger amounts of experimental data, thus providing the opportunities to intensify and extend the fusion researches. The new features of the DAS-T10 along with the existing design principles are reviewed in this paper

  5. Assessment of the coronary venous system in heart failure patients by blood pool agent enhanced whole-heart MRI

    Energy Technology Data Exchange (ETDEWEB)

    Manzke, Robert [University Hospital of Ulm, Department of Internal Medicine II, Ulm (Germany); Philips Research Europe, Clinical Sites Research, Hamburg (Germany); Binner, Ludwig; Bornstedt, Axel; Merkle, Nico; Lutz, Anja; Gradinger, Robert [University Hospital of Ulm, Department of Internal Medicine II, Ulm (Germany); Rasche, Volker [University Hospital of Ulm, Department of Internal Medicine II, Ulm (Germany); Experimental Cardiovascular Imaging, Internal Medicine II, Ulm (Germany)

    2011-04-15

    To investigate the feasibility of MRI for non-invasive assessment of the coronary sinus (CS) and the number and course of its major tributaries in heart failure patients. Fourteen non-ischaemic heart failure patients scheduled for cardiac resynchronisation therapy (CRT) underwent additional whole-heart coronary venography. MRI was performed 1 day before device implantation. The visibility, location and dimensions of the CS and its major tributaries were assessed and the number of potential implantation sites identified. The MRI results were validated by X-ray venography conventionally acquired during the device implantation procedure. The right atrium (RA), CS and mid-cardiac vein (MCV) could be visualised in all patients. 36% of the identified candidate branches were located posterolaterally, 48% laterally and 16% anterolaterally. The average diameter of the CS was quantified as 9.8 mm, the posterior interventricular vein (PIV) 4.6 mm, posterolateral segments 3.3 mm, lateral 2.9 mm and anterolateral 2.9 mm. Concordance with X-ray in terms of number and location of candidate branches was given in most cases. Contrast-enhanced MRI venography appears feasible for non-invasive pre-interventional assessment of the course of the CS and its major tributaries. (orig.)

  6. Clinical application of functional MRI

    International Nuclear Information System (INIS)

    Described is the present state of clinical application of fMRI in the preoperative assessment of brain tumors, and plasticity in and pathophysiology of central diseases. For the tumor resection, fMRI is useful for risk assessment of postoperative nerve dysfunction, for selection of the patient rather suitable for brain mapping at the invasive surgery than at the pre-operation and for guidance of the operation itself. Preoperative fMRI alone can neither distinguish the regions of the primary and secondary functions nor exhibit the relation between the tumor and white matter fibers but there are compensatory means for these drawbacks. Benefit of preoperative fMRI has not yet been based on the evidence on double blind trials. Combination of fMRI imaging and electroencephalography (EEG) finding has shown that, in generalized epilepsy, extensive and stimulated activation occurs in both frontal/occipital regions and in thalamus area, respectively, and that the concomitant lowered activities are conceivably the reflection of burst discharge in normal brain functions. Plasticity in the human brain has been demonstrated by fMRI in cerebral vascular diseases, multiple sclerosis and amyotrophic lateral sclerosis. Pathogenesis of Parkinson disease and depression has been better understood by fMRI investigations revealing regions with elevated and reduced activities. Studies of attention deficit hyperactivity disorder have shown similar change of activities with functional reductions of the right dorsolateral frontal anterior area and of dorsal frontal cingulate gyrus, together with stimulated wider regions to given tasks. As above, fMRI has greatly contributed to our understanding of diseases of central nervous system and is to be expected to expand wider in this field. (T.T.)

  7. In vivo functional connectome of human brainstem nuclei of the ascending arousal, autonomic and motor systems by high spatial resolution 7 Tesla fMRI

    Science.gov (United States)

    Bianciardi, Marta; Toschi, Nicola; Eichner, Cornelius; Polimeni, Jonathan R.; Setsompop, Kawin; Brown, Emery N.; Hamalainen, Matti S.; Rosen, Bruce R.; Wald, Lawrence L.

    2016-01-01

    Object To map the in vivo human functional connectivity of several brainstem nuclei with the rest of the brain by using seed-based correlation of ultra-high magnetic field functional magnetic resonance imaging (fMRI) data. Materials and Methods We used the recently developed template of 11 brainstem nuclei derived from multi-contrast structural MRI at 7 Tesla as seed regions to determine their connectivity to the rest of the brain. To achieve this, we utilized the increased contrast-to-noise ratio of 7 Tesla fMRI compared to 3 Tesla and the time efficient simultaneous multi-slice imaging to cover the brain with high spatial resolution (1.1 mm-isotropic nominal resolution) while maintaining a short repetition time (2.5 s). Results The delineated Pearson’s correlation-based functional connectivity diagrams (connectomes) of 11 brainstem nuclei of the ascending arousal, motor and autonomic systems from 12 controls are presented and discussed in the context of existing histology and animal work. Conclusion Considering that the investigated brainstem nuclei play a crucial role in several vital functions, the delineated preliminary connectomes might prove useful for future in vivo research and clinical studies of human brainstem function and pathology, including disorders of consciousness, sleep disorders, autonomic disorders, Parkinson’s disease and other motor disorders. PMID:27126248

  8. Water uptake patterns and root system architecture of Zea mays in a natural soil under influence of drought stress monitored by MRI

    Science.gov (United States)

    Merz, Steffen; Pohlmeier, Andreas; Seidler, Christina; van Dusschoten, Dagmar; Vereecken, Harry

    2012-04-01

    The interface between roots and soil plays a key role in water transport in the Soil-Plant-Atmosphere-Continuum (SPAC). The transport which changes with the degree of dehydration is influenced by both the hydraulic conductivity of roots and the soil. One important factor in plant growth is the amount of available water in the soil, which correlates directly with soil texture. Water uptake of plant roots and water uptake patterns in soil can be monitored using non-invasive 1H Nuclear Magnetic Resonance Imaging (MRI). In a preceding study the effect of root water uptake and uniform desiccation patterns under drought conditions were observed for Ricinus communis grown in a model medium (Pohlmeier et al. 2008). Continuing these studies, the new aspect is the determination of water uptake patterns and root system architecture in a natural soil. The general challenge of MRI in soils are the inherent fast relaxation times T2* and T2 of the soil matrix. With the use of conventional sequences only water in macropores can be determined. The loss of sensitivity can be overcome by MRI sequences with sufficiently short detection times. In this work we employed and assessed two methods: SPI (Single Point Imaging) detects the T2* relaxation with a dead time of Ricinus Root Uptake Monitored by Magnetic Resonance Imaging" Vadose Zone J. 7: 1010-1017.

  9. Imaging diagnosis of solitary pulmonary nodules on an open low-field MRI system - comparison of two MR sequences with spiral CT

    International Nuclear Information System (INIS)

    Objective: To evaluate and compare two fast gradient-echo sequences (GRE) concerning the visualization of solitary pulmonary nodules with an open low-field MRI system in comparison to computed tomography. Materials and Methods: Fourteen patients with solitary pulmonary nodules detected by spiral CT ranging in size from 6 mm to 42 mm (mean 20 mm) underwent MRI on an open 0.2 T scanner using a spoiled 2D GRE (2D FLASH; TR/ TE/Flip = 100 ms/7.5 ms/30 ) and a totally refocused 2D steady-state GRE (True-FISP; TR/TE/FA = 7.3 ms/3.5 ms/80 ). The image quality concerning artifacts (by flow, breathing and susceptibility) and the morphologic characteristics of the nodules were scored and compared with CT by two independent radiologists. The diameters of the nodules measured by MRI were compared with CT measurements. The sequences were also evaluated with regard to the signal-to-noise ratio (SNR) of the lesion. Results: All lesions were detected with the 2D FLASH sequence. True-FISP failed to find a granuloma with a size of 6 mm. The 2D FLASH was rated significantly superior to true FISP concerning image quality artifacts by susceptibility as well as concerning to CT the presentation of nodule characteristics. In MR images, the size of lesions was significantly smaller than in CT images for both sequences: for 2D FLASH the mean difference was 0.9 mm and for true FISP 2.6 mm. The SNR of the nodules was significantly higher for the 2D FLASH than for the true FISP. Conclusion: In low field MRI, the 2D FLASH sequence is superior to the 2D true FISP sequence in imaging of pulmonary nodules. With the 2D FLASH sequence nodules of 6 mm or larger in size can be visualized. (orig.)

  10. Authenticated Blind Issuing of Symmetric Keys for Mobile Access Control System without Trusted Parties

    Directory of Open Access Journals (Sweden)

    Shin-Yan Chiou

    2013-01-01

    Full Text Available Mobile authentication can be used to verify a mobile user’s identity. Normally this is accomplished through the use of logon passwords, but this can raise the secret-key agreement problem between entities. This issue can be resolved by using a public-key cryptosystem, but mobile devices have limited computation ability and battery capacity and a PKI is needed. In this paper, we propose an efficient, non-PKI, authenticated, and blind issued symmetric key protocol for mobile access control systems. An easy-to-deploy authentication and authenticated key agreement system is designed such that empowered mobile devices can directly authorize other mobile devices to exchange keys with the server upon authentication using a non-PKI system without trusted parties. Empowered mobile users do not know the key value of the other mobile devices, preventing users from impersonating other individuals. Also, for security considerations, this system can revoke specific keys or keys issued by a specific user. The scheme is secure, efficient, and feasible and can be implemented in existing environments.

  11. Single-port-access surgery with a novel magnet camera system.

    Science.gov (United States)

    Terry, Benjamin S; Mills, Zachary C; Schoen, Jonathan A; Rentschler, Mark E

    2012-04-01

    In this paper, we designed, built, and tested a novel single-port access laparoscopic surgery (SPA) specific camera system. This device (magnet camera) integrates a light source and video camera into a small, inexpensive, portable package that does not compete for space with the surgical tools during SPA. The device is inserted through a 26-mm incision in the umbilicus, followed by the SPA port, which is used to maintain an insufflation seal and support the insertion of additional tools. The camera, now in vivo, remains separate from the SPA port, thereby removing the need for a dedicated laparoscope, and, thus, allowing for an overall reduction in SPA port size or the use of a third tool through the insertion port regularly reserved for the traditional laparoscope. The SPA camera is mounted to the abdominal ceiling using one of the two methods: fixation to the SPA port through the use of a rigid ring and cantilever bar, or by an external magnetic handle. The purpose of the magnet camera system is to improve SPA by: 1) eliminating the laparoscope SPA channel; 2) increasing the field of view through enhanced camera system mobility; and 3) reducing interference between the camera system and the surgical tools at the port, both in vivo and ex vivo.

  12. Implementing funding modalities for free access: The case for a "purchasing fund system" to cover medical care

    OpenAIRE

    Philippe, Vinard; Karim, Diop; Taverne, Bernard

    2008-01-01

    The principle of free access to ARVs was recognized in Senegal in 2003. Debate now focuses on its expansion to cover all therapeutic care (consultations, exams, treatment for opportunistic infections). Expenditures incurred by this complementary packet often impede access to care. The main difficulty does not really arise from the need for funding but rather from how this treatment is managed and its impact on the current financing systems. In fact, four types of possible funding exist: (1) p...

  13. Design and analysis of a biometric access control system using an electronic olfactory device to identify human odour characteristics

    OpenAIRE

    McMillan, Stephen

    2000-01-01

    The use of an electronic olfactory device, termed an electronic 'nose', was investigated for the detection of unique human odour characteristics. The detection of these unique odours was applied to the field of biometrics for access control, where a human's unique characteristics were used to authenticate a user of an access control system. An electronic odour sensing device was designed and constructed using an array of conducting polymer gas sensors in order to facilitate the regular screen...

  14. An exploration of the enablers and barriers in access to the Dutch healthcare system among Ghanaians in Amsterdam

    Directory of Open Access Journals (Sweden)

    Boateng Linda

    2012-03-01

    Full Text Available Abstract Background Sub-Saharan African populations are growing in many European countries. Data on the health of these populations are rare. Additionally, many sub-Saharan African migrants are confronted with issues of low socio-economic status, acculturation and language difficulties, which may hamper their access to health care. Despite the identification of some of those barriers, little is known about the enabling factors. Knowledge about the enablers and barriers in access to healthcare experienced is important in addressing their health needs and promoting healthcare access. This study aimed to investigate the enabling factors as well as barriers in access to the Dutch healthcare system among the largest sub-Saharan African migrant group (Ghanaians living in Amsterdam, the Netherlands. Methods Six focus groups were conducted from November 2009 to February 2010. A semi-structured interview guideline was used. Discussions were conducted in English or Twi (Ghanaian dialect, recorded and transcribed verbatim. Analysis was based on the Andersen model of healthcare utilisation using MAXQDA software. Results Knowledge and perceived quality of the health system, awareness of diseases, family and community support, community initiatives and availability of social support were the main enablers to the healthcare system. Difficulties with the Dutch language and mistrust in health care providers were major barriers in access to healthcare. Conclusions Access to healthcare is facilitated mainly by knowledge of and the perceived efficiency and quality of the Dutch healthcare system. However, poor Dutch language proficiency and mistrust in health care providers appear to be important barriers in accessing healthcare. The enablers and barriers identified by this study provide useful information for promoting healthcare access among this and similar Sub-Saharan African communities.

  15. Access Management Processes in Cargotec’s Financial Reporting Systems : An approach to improve throughput time and increase quality

    OpenAIRE

    Magnusson, Johan

    2013-01-01

    This study investigates the access management process for a globally implemented financial reporting system. Through this research the goal is to find inefficiencies and bottlenecks in the process which prohibit the access management process from running at optimal speed. Best practices from the fields of operations management and business process design are synthesized to create a conceptual framework which incorporates the concepts at the heart of well-designed and well-implemented bus...

  16. RFID card based access control system with counter for Indus Complex

    International Nuclear Information System (INIS)

    As per norms of the Atomic energy regulatory board (AERB) to operate a facility in round the clock which has a potential of radiation exposure, radiation safety rules are to be followed. Indus -1 and Indus-2 are synchrotron radiation sources which are open for various users round the clock. To monitor the persons inside the defined zone at any given time, a system is setup consisting of RF ID cards and their readers along with dedicated software. Software is developed in Visual Basic and uses UDP network protocol for receiving data from readers installed at various locations and connected to local area network. The paper describes the access control scheme followed in Indus Accelerator Complex. (author)

  17. Joint robustness security in optical OFDM access system with Turbo-coded subcarrier rotation.

    Science.gov (United States)

    Zhang, Lijia; Liu, Bo; Xin, Xiangjun; Wang, Yongjun

    2015-01-12

    This paper proposes a novel robust physical secure method for optical orthogonal frequency division multiplexing (OFDM) access system based on Turbo-coded subcarrier rotation. It can realize a secure communication while keep robustness to channel noise. The subcarrier rotation is controlled by the interleaver module of Turbo coding, which is under the charge of Logistic map. The random puncturing can further enhance the security. The channel feedback can ensure the puncturing module working at a suitable coding rate. A 72.28 Gb/s encrypted 16QAM-OFDM signal is successfully demonstrated in the experiment. The results show robust performance under different channel noise conditions and good resistance to illegal optical network unit (ONU).

  18. Multiagent Q-Learning for Aloha-Like Spectrum Access in Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Husheng Li

    2010-01-01

    Full Text Available An Aloha-like spectrum access scheme without negotiation is considered for multiuser and multichannel cognitive radio systems. To avoid collisions incurred by the lack of coordination, each secondary user learns how to select channels according to its experience. Multiagent reinforcement leaning (MARL is applied for the secondary users to learn good strategies of channel selection. Specifically, the framework of Q-learning is extended from single user case to multiagent case by considering other secondary users as a part of the environment. The dynamics of the Q-learning are illustrated using a Metrick-Polak plot, which shows the traces of Q-values in the two-user case. For both complete and partial observation cases, rigorous proofs of the convergence of multiagent Q-learning without communications, under certain conditions, are provided using the Robins-Monro algorithm and contraction mapping, respectively. The learning performance (speed and gain in utility is evaluated by numerical simulations.

  19. Multiagent -Learning for Aloha-Like Spectrum Access in Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Li Husheng

    2010-01-01

    Full Text Available An Aloha-like spectrum access scheme without negotiation is considered for multiuser and multichannel cognitive radio systems. To avoid collisions incurred by the lack of coordination, each secondary user learns how to select channels according to its experience. Multiagent reinforcement leaning (MARL is applied for the secondary users to learn good strategies of channel selection. Specifically, the framework of -learning is extended from single user case to multiagent case by considering other secondary users as a part of the environment. The dynamics of the -learning are illustrated using a Metrick-Polak plot, which shows the traces of -values in the two-user case. For both complete and partial observation cases, rigorous proofs of the convergence of multiagent -learning without communications, under certain conditions, are provided using the Robins-Monro algorithm and contraction mapping, respectively. The learning performance (speed and gain in utility is evaluated by numerical simulations.

  20. System and method for integrating and accessing multiple data sources within a data warehouse architecture

    Science.gov (United States)

    Musick, Charles R.; Critchlow, Terence; Ganesh, Madhaven; Slezak, Tom; Fidelis, Krzysztof

    2006-12-19

    A system and method is disclosed for integrating and accessing multiple data sources within a data warehouse architecture. The metadata formed by the present method provide a way to declaratively present domain specific knowledge, obtained by analyzing data sources, in a consistent and useable way. Four types of information are represented by the metadata: abstract concepts, databases, transformations and mappings. A mediator generator automatically generates data management computer code based on the metadata. The resulting code defines a translation library and a mediator class. The translation library provides a data representation for domain specific knowledge represented in a data warehouse, including "get" and "set" methods for attributes that call transformation methods and derive a value of an attribute if it is missing. The mediator class defines methods that take "distinguished" high-level objects as input and traverse their data structures and enter information into the data warehouse.